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Re-Thinking HOV - High Occupancy Vehicle Facilities and the Public Interest

ClickHERE for graphic.

                        LIST OF ABBREVIATIONS

Caltrans       California Department of Transportation
CARB           California Air Resources Board
CMAQ           Congestion Mitigation and Air Quality (federal
EIS            Environmental Impact Statement
EPA            Environmental Protection Agency
FHWA           Federal Highway Administration
HOV            High occupancy vehicle
ISTEA          Intermodal Surface Transportation Efficiency Act of
SCRTD          Southern California Rapid Transit District (now the
                    Metropolitan Transit Authority)
SOV            Single occupancy vehicle
SIP            State implementation plan (under the federal Clean
                    Air Act)
TRB            Transportation Research Board
VMT            Vehicle miles traveled
USDOT          U.S. Department of Transportation


This research was funded partly by the Chesapeake Bay Foundation
and the Bullitt Foundation. It also would not have been possible
without the astute suggestions of many individuals, among them
Henry Bain, Robert T. Babbitt, Bob Berry, Eric Bruun, Sarah
Campbell, Daniel Carlson, Stuart Clark, Nancy Jewell Cross,
Flannery Davis, Mike Ferro, Robert Fellows, Rupert Friday, Charles
A. Fuhs, Ann Haynes, John Holtzclaw, Mayer Horn, Gary Idleburg, Les
Jacobson, Larry King, Nancy F. Leman, Dick Nelson, Richard H.
Pratt, Michael Replogle, Dan Ridgeway, Jerry Schneider, William L.
Schroeer, Charles Smith, Alvin L. Spivak, Heidi Stamm, Michael
Vandeman, Vukan Vuchic, and Lisa Wormser. Agencies that provided
useful information include Caltrans, Chicago Department of
Transportation, Chicago Transit Authority, Federal Highway
Administration, Los Angeles Department of Transportation, Maryland
Department of Transportation, Massachussetts Department of
Highways, Metro (King County), Metropolitan Transit Authority (Los
Angeles), New Jersey Department fo Transportation, Virginia
Department of Transportation, Washington State Department of
Transportation, and other agencies and organizations. Graphic
Designer: Terry Coker Peterson, Chesapeake Bay Foundation


Christopher K. Leman, Ph.D.,is executive director of the Institute
for Transportation and the Environment [85 E. Roanoke Street,
Seattle WA 98102; (206)322-5463]. He presented versions of this
paper at 1994 conferences of the Institute of Transportation
Engineers and the Transportation Research Board.

Preston L. Schiller, Ph.D.,is coeditor of the Transportation
Bulletin and the Gridlock Gazette,publications of the Institute for
Transportation and the Environment. He is also a coordinator of
ALT-TRANS, the Washington Coalition for Transportation
Alternatives, and chairs the Sierra Club's national Urban
Environment committee.

Kristin Pauly is transportation program coordinator for the
Chesapeake Bay Foundation. She is also coordinator of the
Washington Regional Network, a growth management and transportation
alliance of public interest groups from throughout the D.C.
metropolitan area.

For Additional copies contact

162 Prince George Street
Annapolis, Maryland 21401
$3.00 per copy for postage & handling

                           ReThinking HOV 

RECOMMENDATION 1: in congested urban areas, newly constructed
roadway lanes should be primarily or exclusively for public

RECOMMENDATION 2: HOV lanes should be connected to one another and
to key transit origins, destinations, and cross routes,
construction investment should avoid segments that have little
prospect of being connected with the larger network.

RECOMMENDATION 3: Newly constructed HOV lanes should be HOV on a
24-hour basis, not just during peak-period or in the peak-

RECOMMENDATION 4: The design of transit-only lanes should be
determined by the needs of buses and should not envision future use
by automobiles.

RECOMMENDATION 5: When they contribute to the cost of HOV lanes,
transit agencies should insist on limitations as to which vehicles
can use the lanes. Buses should have first priority. Paratransit
and approved carpools should be allowed only with binding
commitments that their numbers be limited and not hamper bus
operations. Emergency vehicles should be welcomed to emphasize the
lane's special status.

RECOMMENDATION 6: Regional transportation plans, spending programs,
air quality conformity analyses, and other actions must fully
analyze the increases in solo driving and air pollution that would
result from each HOV lane construction proposal. Governments should
adopt standards to discourage projects that would have these

RECOMMENDATION 7: Construction of new HOV lanes that are not
transit-only should not be listed as a transportation control
measure under the federal Clean Air Act unless their long run air
quality impacts are shown to be positive in a rigorous analysis.

RECOMMENDATION 8: A car with two occupants is low occupancy, not
high, and should not be encouraged by new construction. If 2+ is
adopted as a minimum occupancy level for HOV lanes, that status
should be conditional. The lane should be upgraded based on
performance or on an automatic schedule for higher occupancy or
bus-only status.

RECOMMENDATION 9: States with poor HOV lane enforcement records
should have to return part of the federal funds used to construct
the lanes and should have a harder time qualifying for future HOV
lane construction funds.

RECOMMENDATION 10: To help prevent backsliding, peak-period HOV
lanes should be extended to 24-hour operation. Existing 24-hour HOV
lanes should remain so.

RECOMMENDATION 11: Federal or state funding of HOV lanes should be
with a "money-back guarantee" requiring return of the funds if the
HOV lanes are subsequently changed to general purpose lanes.

RECOMMENDATION 12: Do not impose vehicle-flow requirements on HOV
or bus-only lanes when people-carrying capacity is the more
relevant criterion.

RECOMMENDATION 13: Bus-only and HOV lanes should be established
first by conversion from existing general purpose roadways. New
lane construction should be a second choice, if it is chosen at
all. No lane that is HOV at peak periods only should be
constructed, such lanes should be established only by conversion.

RECOMMENDATION 14: Urban areas should establish contingency plans
for the conversion of general purpose lanes to exclusive HOV or
transit use in the event of an energy shortage, a disaster, or
nonattainment of clean air standards.

RECOMMENDATION 15:Highway design manuals, road fund programming
guidelines, transportation laws and plans, and other guidance
should require study of the conversion to HOV of general purpose
lanes as the prime alternative when any construction of new general
purpose or HOV lanes is being considered.

RECOMMENDATION 16: Conversion to HOV from general purpose lanes
should always be preferred to "take-a-rail."

                          TABLE OF CONTENTS

EXECUTIVE SUMMARY. . . . . . . . . . . . . . . . . . . . . . . . . 1

I.   INTRODUCTION. . . . . . . . . . . . . . . . . . . . . . . . . 3


1.   History of transit-only and HOV facilities. . . . . . . . . . 3

2.   Historical perspective on ridesharing . . . . . . . . . . . . 3

3.   National policy on exclusive lanes. . . . . . . . . . . . . . 4

Ill. TRANSIT: THE FORGOTTEN HOV. . . . . . . . . . . . . . . . . . 6

IV.  HOV LANES AND AIR QUALITY . . . . . . . . . . . . . . . . . .10


VI.  ENFORCEMENT AND SAFETY. . . . . . . . . . . . . . . . . . . .15




1.   Least cost planning: efficiency, not expansion. . . . . . . .24

2.   The pricing alternative . . . . . . . . . . . . . . . . . . .25

3.   Conclusion. . . . . . . . . . . . . . . . . . . . . . . . . .26

BIBLIOGRAPHY . . . . . . . . . . . . . . . . . . . . . . . . . . .27

                          EXECUTIVE SUMMARY

Traffic problems, financial constraints, and a desire for cleaner
air are forcing reexamination of traditional efforts to expand the
capacity of roads and highways. A popular proposal in recent years
has been to build additional lanes and other facilities for high
occupancy vehicles (HOVs) - buses, passenger vans, and carpools.
This paper reviews the history of the HOV concept and explores the
assumptions underlying the expansion of HOV facilities.

Some in highway and transit agencies argue that the construction of
HOV lanes is a revolutionary new direction that will improve
transportation efficiency, provide incentives for higher occu-
pancies, promote transit, and reduce car trips, vehicle miles
traveled, and air pollution. The authors of this paper question
these claims and suggest that new HOV lane construction, as now
being planned and implemented, is simply increasing the roadway
space devoted to the automobile.

     A car with two occupants is a low occupancy vehicle, not high
     occupancy: a date is not a carpool.

Constructing HOV lanes has many of the same negative impacts as
constructing general purpose lanes - and once constructed, HOV
lanes face the constant pressure of being opened up to general
purpose traffic (at nonpeak periods, or all the time), or to the
smallest possible carpool (of two). Constructing HOV lanes has high
initial costs and many recurring costs, especially for
maintenance - even aside from its high social and environmental
costs, which are both initial and recurring.

Any proposal for construction of a new HOV lane should be closely
examined. It should be compared with the alternative of converting
an existing general purpose lane - a far cheaper alternative, and
one that creates a greater incentive to switch from solo driving.

When the goal is "to move more people in fewer vehicles and
encourage people to use high occupancy vehicles (see page 5)," it
becomes clear that transit buses are the workhorses of many HOV
lanes and would carry more people if policies were designed to that
end. What is best for transit (buses and passenger vans) should be
determined first and separately from the issue of what is best for
carpools. Lanes available to buses but not to automobiles are a
more effective way to promote transit. As transit and emergency
vehicle lanes, they should be protected as a public utility.
Carpools on these lanes should be allowed-if at all-only with
limitations, among them that they be fully loaded or nearly so. A
car with two occupants is a low occupancy vehicle, not high
occupancy: a date is not a carpool.

In the long run HOV lanes may worsen air quality, reduce transit
mode share, and increase vehicle trips and the miles driven.
Constructing HOV lanes on long stretches of freeway encourages
urban sprawl and diverts resources from needed improvements in
transit within cities.

Only if existing facilities are used efficiently can we assure that
public dollars are spent wisely. Over time and with new
technologies, pricing is likely to become a more reliable way to
moderate roadway demand and reduce the need to build either HOV or
additional general purpose lanes.

A Report by the CHESAPEAKE BAY FOUNDATION                          1

                           ReThinking HOV


Few would dispute the need for a greater proportion of traffic to
be in buses, vanpools, and carpools. The debate is whether the best
means to that end is to build new lanes and other facilities that
admit not only buses and other genuinely high occupancy vehicles
(HOVs), but also cars carrying as few as two people. This paper
shows that HOV lane construction is in many ways creating rather
than solving traffic problems. [see inside front cover for list of

I.   Historical background


Early in this century, streetcars enjoyed their own rights-of-way,
often in the roadway median. As rails were paved over, the buses
that replaced the streetcars generally shared the lanes with other
motor vehicles. As bus service began to suffer from the growing
traffic congestion, buses were given their own lanes. Apparently
the earliest U.S. instance was in 1939, with establishment of more
than a mile of lanes on Chicago's North Sheridan Road to bus-only
during peak traffic flow periods (termed "peak periods" in this
paper) in the direction of peak flow (termed "peak direction" in
this paper); local traffic was still allowed on the lanes. The
number of bus-only lanes throughout the country increased partic-
ularly in the 1960s and 1970s, with some on a 24-hour basis
[Levinson, 1973; Turner].

Freeway lanes and ramps have also been set aside for buses. One of
the first (1962) was a lane in each direction on the San Francisco-
Oakland Bay Bridge (I-80) for bus and construction traffic when the
bridge was being rebuilt to pave over the existing passenger rail
tracks. Bus patronage across the bridge increased, but went down
again when the lanes were restored to general purpose traffic upon
completion of the rebuilding. This omission was partially corrected
in 1970 when a bus lane was established on the eastern approach to
the bridge; alongside it, two additional lanes were also set aside
for carpools in 1971. Another early case (I-970) was a morning bus-
only lane on the New Jersey Turnpike (I-495) approaching the
Lincoln Tunnel into Manhattan.

The first U.S. freeway lanes built solely for buses were probably
the Shirley Highway Busway on I-395 in northern Virginia (1969). In
1973, the busway was opened to carpools, apparently the first U.S.
instance in which buses and carpools officially shared a longhaul
HOV lane. HOV lanes on freeways have spread, and now can be found
in more than 20 urban areas of the United States and Canada, with
projects in other areas being planned [Batz, 1986; Turnbull, 1990;
Fuhs, 1993].


Carpools existed long before exclusive lanes and other facilities
were set aside to give them a relative advantage over driving
alone. Although the term "high occupancy vehicle" had not been
invented in the early years of the automobile, most automobiles
operated most of the time at high occupancies; the scarcity of
vehicles, fuel, roads and parking areas required it. In fact, many
cars prior to the 1950s were designed to accommodate five or six
occupants in relative comfort. Economic necessity made carpooling a
routine part of life.

A Report by the CHESAPEAKE BAY FOUNDATION                          3

The larger families of that era typically "piled into the family
car." Neighbors would share the ride to work, school, grocery
shopping, the movies, and so on. Employers, schools, and clubs
helped connect drivers with potential riders. Hitchhiking was
common and encouraged. Wartime gasoline rationing encouraged
ridesharing, as did publicity campaigns. One World War II era
advertisement portrayed the grim message, "If you ride alone, you
ride with Hitler!"

But this tradition was greatly weakened by postwar policies to
build roads and parking lots and to encourage an automobile-
dependent lifestyle. As the two-car family, the three-car garage,
and free parking at work became commonplace, carpooling declined.
According to the 1990 U.S. census, average vehicle occupancy for
commuting has dropped to 10.9, the lowest level ever recorded.
Between 1980 and 1990-when the nation's civilian workforce was
increasing by 18.6 million-average daily carpools to work declined
from 19 million to 15 million. The largest declines occurred in
carpools of four or more (over 50 percent decline) and three
(almost 40 percent decline). Even two-person carpools for commuting
went down by ten percent. Between 1980 and 1990 daily transit
ridership to work also declined slightly to six million; solo
driving was the only commuting mode that increased, to a record-
high 84.2 million-three quarters of all trips [Pisarski].

The decline in ridesharing has coincided with unprecedented
governmental peacetime efforts to promote ridesharing. In the
energy crises of the 1970s, telephone services were established to
encourage ridematching. By the 1990s, many large companies had
programs to encourage their employees to take transit, vanpools, or
carpools, with such incentives as free or lower-cost parking.

ClickHERE for graphic.

Even as carpools decreased in the 1970s, a new term emerged, "high
occupancy vehicle." It seems doubtful that the average carpooler or
busrider prefers this term and its acronym HOV. More common in
public parlance are terms like "carpool lane" or "busway," even
though the lanes often combine both buses and carpools and (in off-
peak periods) single occupancy vehicles. The concept of HOV
attempts to encompass carpools, vanpools, and buses in the same
category. As discussed in later sections, it is as awkward a fit on
the road as it is in terminology.


Beginning in the 1970s, officials in the Urban Mass Transit
Administration (now the Federal Transit Administration) recognized
the advantages of exclusive transit lanes and encouraged their
funding-indeed sometimes in preference to rail lines. In the 1970s
the Federal Highway Administration (FHWA) began to allow (but did
little to encourage) state highway agencies to spend federal funds
on HOV

                                                      ReThinking HOV

lanes. This policy changed with an October 1990 memorandum from the
administrator stating that, "FHWA strongly supports the objective
of HOV preferential facilities and encourages the proper
application of HOV technology." Regional administrators were
directed to promote HOV lanes and related facilities.

Two laws in the early 1990s cemented a national commitment to HOV
lane construction. The Clean Air Act Amendments of 1990 listed HOV
lanes as one of the transportation control measures that could be
included in state implementation plans to attain federal air
quality standards. The 1990 amendments also deny the administrator
of the Environmental Protection Agency the authority to block FHWA
from funding 24-hour HOV lanes as part of the sanctions for a
state's failure to comply with the Clean Air Act, if the secretary
of transportation wishes to approve the FHWA funds. Withholding of
FHWA funds for most other roadway capacity improvements is a
sanction available to the EPA administrator without being blocked
by the secretary of transportation.

The Intermodal Surface Transportation Efficiency Act (ISTEA) of
1991 established some new cautions in the federal funding of
general purpose lanes. Yet ISTEA encouraged the construction of HOV
lanes, which were made eligible for Congestion Mitigation and Air
Quality (CMAQ) funds in regions not attaining federal air quality
standards. CMAQ funds may be spent on new HOV lane construction,
even if the HOV designation holds only at peak travel times or in
the peak direction.

ISTEA also provided that under the Interstate Maintenance Program,
only HOV projects would receive the 90 percent federal matching
ratio formerly available for the addition of general purpose lanes.
And ISTEA permitted state authorities to define an HOV as having a
minimum of two occupants (HOV-2).

Until overruled by Congress, FHWA had insisted that 2+:

     accomplishes little more than rearranging traffic in lanes
     according to number of occupants. The number of vehicles using
     the HOV lane may increase but this is offset by a decrease in
     the average vehicle occupancy in the other lanes. Use of HOV-2
     does not generally accomplish the purpose for which priority
     treatments are implemented; i.e., to move more people in fewer
     vehicles and encourage people to use high occupancy vehicles
     [FHWA, February 4,1985].

During the ISTEA debates, Congress did not adopt a proposal by
Senator Daniel Patrick Moynihan (Democrat-N.Y.) that would have
required states to return a portion of any federal funds used to
construct an HOV lane if the lane were later converted to general
purpose use. ISTEA also did not (as some proposed) give preference
to conversion of general purpose lanes as a means to establish HOV
lanes. There is no explicit requirement in the parts of ISTEA
referring to HOV lanes that the conversion alternative be studied
and compared with construction alternatives, although the
regulations implementing ISTEA can be interpreted as requiring such
a comparison [USDOT].

A Report by the CHESAPEAKE BAY FOUNDATION                          5

III. Transit: The forgotten HOV

RECOMMENDATION 1: In congested urban areas, newly constructed
roadway lanes should be primarily or exclusively for public

Public transit buses are the workhorses of many urban freeway HOV
lanes, and would do even more if buses received higher priority. As
shown by Table 1, inside back cover, [Pratt, 1991 ] even on HOV
lanes that admit carpools, more than a third of the travelers are
riding by bus, and on some routes they outnumber those in carpools
and vanpools. Clearly, many HOV lanes are high performers only
because of their usefulness to transit.

The most impressive performance is on bus only lanes. The nation's
(and possibly the world's) best "people-carrying" road lane is New
Jersey's Route 495, where a morning bus-only lane carries more than
20,000 people an hour into the Lincoln Tunnel. The lane serves 30
percent of all trans-Hudson River commuters, more than the combined
total of all 12 general purpose lanes next to it [Home and Quelch].
Also notable is the Ottawa Carleton area's network of transitways,
which help OC Transpo carry 30 percent of all vehicle-based travel
and 70 percent of peak hour trips to downtown [Bonsall].

Many more bus passengers are carried on exclusive bus lanes that
are located on surface streets and are too numerous to list. Bus-
only lanes can be found in every major city and in many smaller

An advantage of buses over carpools is that they require much less
road space per passenger [Vuchic et al.]. At freeway speeds, a full
bus can carry as many people as a lane of carpools up to a mile
long. Buses are rarely so numerous as to cause a traffic Jam, a
fact that helps protect the time savings of riding in a bus-only
lane. Traffic jams are caused mostly by automobiles, which, even
when full, require a lot more road space per passenger, and thus
slow one another down.

Any discussion of HOV lanes should begin with the question, "What
is best for transit?" A common argument in favor of HOV lanes and
other facilities is that they promote use of buses. That is not
always true. Certainly preferred access for buses can speed
schedules, use equipment and drivers more efficiently, and improve
reliability and safety. But these benefits are lessened or lost
when a bus-only lane is opened to other traffic. A leading textbook
on transit facilities observes that allowing other vehicles on bus
lanes "is always harmful to transit: buses can only lose from it,
while all the benefits are accrued by their competitors, private
autos" [Vuchic, 1981, p. 260]. Yet a survey of past evaluations of
HOV lanes found in them almost no discussion of bus service
productivity, schedule adherence, or safety [Turnbull, 1991, p.

Ongoing pressure to open bus lanes to carpools could diminish or
eliminate the lanes' relative advantages for buses. Bus-only lanes
provide time and/or service improvements to riders. When an attempt
is made to transfer these benefits to carpools by opening the bus
lane to them, the bus riders' advantages are lost. When the El
Monte and Shirley Highway busways were opened to carpools, many of
the resulting carpoolers were former bus riders. Automobile trips
increased as transit ridership stagnated. The same sequence
occurred when carpool lanes began to compete with the bus lanes on
the east

6                                                     ReThinking HOV

approach to the San Francisco-Oakland Bay
Bridge [Beroldo].

RECOMMENDATION 2: HOV lanes should be connected to one another and
to key transit origins, destinations, and cross routes.
Construction investment should avoid segments that have little
prospect of being connected to a larger network.

Currently, there are few HOV lanes and they rarely connect to each
other. This is more of a problem for buses than for carpools, which
can take alternative routes. Most of the existing mileage of HOV
lanes is on long commuting routes. The available HOV lanes are
usually not those that would have been chosen based on transit
considerations alone. To pick up and discharge passengers at either
end of the commute, buses must enter heavy general purpose traffic.
And many freeway HOV lanes-especially those on inside lanes far-
thest from ramps-are not convenient to exits, discouraging bus
stops en route. Flyer stops on freeways-in theory a way to avoid
the need to exit the freeway to pick up and discharge passengers-
offer little passenger convenience and safety. Most are just too
difficult for the pedestrian to reach, and the noise, pollution,
security, and amenities are often unacceptable. A better
alternative is a freeway pullout that connects with arterial bus
service along the freeway.

Freeway buses gain time over long distances, but forego passengers
along the way. This tendency to favor long-haul over shorter bus
routes has serious financial and civic consequences. The longer
routes are often the worst money-losers, depending on the shorter
local routes as "cash cows." Thus the shorter routes-depended on by
many urban residents, especially the low-income-end up with less
funding. Meanwhile, these shorter routes receive less benefit from
freeway HOV lanes. Bus-only curb lanes and/or other transit
priority measures on surface streets are most helpful to these

Since Houston is often cited as a case where buses have benefitted
from exclusive freeway lanes, it is interesting that transit
managers there were originally unenthusiastic about the proposed
busways. Feeling that Houston's freeways were poorly located
relative to transit corridors, they sought the establishment of a
network of bus lanes on arterial roads [Levinson, 1973]. It was
only after this plan was rejected by local governments that Houston
transit officials became reconciled to relocating some bus routes
to the freeways.

RECOMMENDATION 3: Newly constructed HOV lanes should be HOV on a
24-hour basis, not just during peak-period or in the peak-

Commuting represents barely one quarter of trips, and its share is
declining; ridesharing should be promoted around the clock, and
especially for the growing proportion of trips that are not a
commute. Yet a growing number of lanes give preference to HOVs and
buses only during weekday peak periods and in the peak direction-
sacrificing any relative advantage for carpoolers and bus riders at
other times and denying buses a standard route. Only if the lanes
are on or near a 24-hour basis can they help provide relief from
the congestion that occurs on holidays, weekends, and during major
events and freeway incidents.

A Report by the CHESAPEAKE BAY FOUNDATION                          7

RECOMMENDATION 4: The design of transit-only lanes should be
determined by the needs of buses and should not envision future use
by automobiles.

Lanes designed for carpools must be engineered to more expensive
standards than busonly lanes. An Institute of Transportation
Engineers report suggests that standards from the American
Association of State Highway and Transportation Officials (AASHTO)
cause the overdesign of exclusive bus lanes:

     Many designers and operators of HOV facilities are of the
     opinion that the AASHTO Design Standards are not appropriate
     for bus-only applications. Since bus-only applications operate
     with professional drivers who drive the same route day after
     day, it appears that narrower shoulders, tighter curves, and
     different stopping sight distance conditions are appropriate
     [ITE, 1988].

With design standards tailored to the needs of buses, a bus-only
lane would not be as expensive to construct or require as much
roadway as one open to carpools. The fact that a busonly lane would
not meet the standards for use by automobiles would also help
prevent its later conversion to carpool or general purpose use. The
argument is sometimes made that an HOV lane is a "placeholder" for
a future passenger rail system. Since rail lines generally require
much less right-of-way than do HOV lanes that are engineered for
automobiles, the narrower bus-only lanes would seem a more
appropriate placeholder.

As discussed in a later section, there has been considerable
backsliding of bus or HOV lanes to general purpose use. A lane
devoted exclusively or primarily to buses will always be envied and
be regarded as "underutilized" by motorists who wish to use it. To
allow policy to be dictated by envious motorists is to condemn
buses to being slowed down in a sea of carpools, many with only two
occupants. In congested urban areas, any new lane construction
should be designed for buses alone to help ensure that its
effectiveness will not later be destroyed by carpools or general
purpose traffic.

RECOMMENDATION 5: When they contribute to the cost of HOV lanes,
transit agencies should insist on limitations as to which vehicles
can use the lanes. Buses should have first priority. Paratransit
and approved carpools should be allowed only with binding
commitments that their numbers be limited and not hamper bus
operations. Emergency vehicles should be welcomed to emphasize the
lane's special status.

Road space is a scarce good that needs to be allocated among
competing social purposes. By the definitions that now prevail, two
shoppers chasing a bargain, or two tourists in a motor home are a
carpool with priority in use of the road; the availability of the
HOV lane may induce their trip, and their presence in the lane may
slow down buses. A simple head count requirement is not enough.
Beyond a head-count, policymakers should consider whether a carpool
actually eliminates any trips.

A concert or sporting event with a lot of cars that arrive fully
loaded is not the height of success. Carpooling to such events has
always been common, but the result is still pollution,

8                                                     ReThinking HOV

Traffic, and collisions. Given the parallel trips of many carpools,
a large proportion of those attending a major event should arrive
by transit or bicycle. With wise policies, it can be done.
Toronto's Skydome stadium, sold out for much of the Bluejays'
season, offers only 350 parking spaces; 90 percent of the fans
arrive by a means other than the automobile.

To ensure that buses have priority use of HOV lanes, policymakers
could broaden the definition of transit to include paratransit
(special vehicles for the elderly or handicapped and vehicles that
provide special services, such as airport shuttles and registered
vanpools and carpools). If commute trips are judged to be priority
trips and buses cannot fully serve them, then vanpools and true
high-occupancy carpools could be allowed on the lanes.

Transit agencies could "deputize" officially registered, carpools
and vanpools. Some already do sponsor vanpools and carpools-
sometimes in vehicles furnished by the agency and with an agency
logo. Vanpools must be registered to have access to the transit
lanes on the Long Island and Gowanus Expressways. The future use of
41 smart cards" (readable by electronic equipment) could monitor
access to a special lane, greatly simplifying enforcement.

Airport shuttles are paratransit that would be a candidate for
using a bus lane. Various van services directed at special
populations (elderly, disabled, etc.) might be defined as paratran-
sit so long as they are reducing low-occupancy vehicle travel. To
facilitate paratransit, it would be necessary Oust as with buses)
to allow access to HOV lanes when these vehicles are on the way to
or from a fare, even if they are below the occupancy criterion. If
taxicabs are allowed, it should be only on condition that they be
multipassenger and multidestinational, and only if more buses and
other true HOVs have been accommodated. On the Long Island
Expressway (I-495) approach to the Queens Midtown Tunnel-a major
airport route-it is difficult to justify the current admission of
taxicabs to the bus lanes when shuttle vans and non-registered
buses are now excluded.

ClickHERE for graphic.

Emergency vehicles already have access to most transit-only lanes;
formally recognizing this use would help protect the lanes from
takeover by low and single-occupancy vehicles. The lanes might be
explicitly renamed as "transit and emergency vehicle lanes," a
designation that would aid in public acceptance of the need to keep
them clearer than a general purpose lane.

Bicycles are increasingly receiving exclusive lanes. ISTEA
prohibited state and local governments from defining bicycles (and
motorcycles) as single occupancy vehicles. In central business
districts or where buses are infre-

A Report by the CHESAPEAKE BAY FOUNDATION                          9

quent, it may be feasible for bicycles to share a bus lane, as on
the Ardmore Busway in the Philadelphia suburbs. Toronto's Bay
Street Clearway, which has allowed bicycling since its
establishment, attracted an 80 percent increase in bicycle travel
in the project's first six months. However, free use of the lanes
by taxicabs raises serious bicycle safety issues.

Even while bicycles are prohibited from many HOV lanes, motorcycles
often are allowed. The motorcycle is by design a low-occupancy
vehicle. The now common high-powered models also consume a great
deal of fuel. Per rider, motorcycles pollute about as much as
automobiles. And they are more collision prone and more dangerous
in a collision than passenger cars. The encouragement of motorcycle
use that comes with allowing them to use HOV lanes should be

Proposals to open HOV lanes to solo motorists driving "clean
vehicles" have even less to recommend them. However clean their
exhaust, solo motorists are an inefficient use of roadway space.

There are a few situations when some general purpose traffic can be
permitted on a transit only or HOV lane, as in a genuine emergency.
Solo drivers are now allowed to enter many bus-only curb lanes when
they must make a right turn. In some cases, local traffic would
need to be allowed on an HOV lane converted on an arterial as a way
to overcome opposition; some method (e.g. electronic "smart cards")
would need to be found to prevent this privilege from being abused

Increasing proportions of federal, state, and local transit budgets
are being spent to construct HOV lanes that mix buses with car-
pools. Meanwhile, some former bus-only lanes have been opened to
carpools or are about to be. For their money, transit agencies
should obtain assurances that buses in existing lanes will not
become mired in carpool traffic-or later by general purpose
traffic. And they should insist that HOV lanes-especially any new
ones-guarantee bus conditions approaching those that would be
available from a bus-only lane.

IV.  HOV lanes and air quality

RECOMMENDATION 6: Regional transportation plans, spending programs,
air quality conformity analyses, and other actions must fully
analyze the increases in solo driving and air pollution that would
result from each HOV lane construction proposal. Governments should
adopt standards to discourage projects that would have these

RECOMMENDATION 7: Construction of new HOV lanes that are not
transit-only should not be listed as a transportation control
measure under the federal Clean Air Act unless their long run air
quality impacts are shown to be positive in a rigorous analysis.

Does building HOV lanes improve air quality? It is claimed in a
California Air Resources Board report [1991] that new HOV lanes
achieve reductions in congestion and in vehicle miles traveled. If
this view is correct, HOV lane construction is still a very expen-
sive air quality measure. A study done in the San Diego area found
it to be the least cost-

10                                                    ReThinking HOV

effective air quality measure of all those studied [San Diego
Association of Governments, 1991]. But some research suggests that
in the long run, congestion and vehicle miles traveled would not go
down, and that air pollution would be worsened by HOV lane

Jon Kessler and Will Schroeer, two EPA economists, provide a
thoughtful discussion of the long run impacts of HOV lane
construction [Kessler and Schroeer, 1992] [Forthcoming in
Transportation: An International Journal, 1994]. Taking the
Washington, D.C., area as their case study, they posit a 334-mile
network of HOV lanes-quite an increase over the existing 75 miles.
They find that although carpooling would substantially increase,
vehicle miles traveled would be only slightly less than if the same
mileage of general purpose lanes had been built. Furthermore, air
quality would not be appreciably better.

     Unless the HOV lane offers a minimum of 5 to 10 minutes of
     travel time savings, its success can be expected to be
     marginal at best.

How could solo commuting go down without appreciably reducing the
total amount of driving? For one thing, ridesharing takes some
additional driving. A rendezvous with fellow carpoolers or a trip
to the park-and-ride can lengthen the overall journey to work.
Also, some of the carpools are formed from former transit riders,
so that vehicle trips may actually be increased by HOV lane

And why would air quality not improve considerably? As much as half
of an average trip's pollution is during the engine's warm-up
("cold start") and cool-down ("hot soak"). When people drive to
meet a bus or carpool, their car emissions are still high enough
that the air quality benefits of their ridesharing are minimal
[EPA, 1992]. More effective air pollution strategies are those that
bring busriders or carpoolers together with a minimum of additional

Another problem: construction of an HOV lane on a freeway
encourages more solo driving on that freeway. The new lanes
increase road space for the solo driver by removing many carpools,
vans, and buses-and even some solo drivers who illegally drive on
the HOV lanes-from the general purpose lanes. By a phenomenon known
as latent demand, solo drivers who had previously taken the bus,
stayed home, or driven at another time or by another route are
attracted by the decline in congestion [Newman and Kenworthy].

The increase in solo driving counteracts many of the apparent
advantages of newly constructed HOV lanes. HOV authorities Don
Capelle and Dennis Christiansen observe that "HOV lanes are a
congestion-dependent transportation improvement; they only work
well when the main freeway lanes are highly congested. Unless the
HOV lane offers a minimum of 5 to 10 minutes of travel time
savings, its success can be expected to be marginal at best"
[Capelle and Christiansen]. Recognizing this reasoning, the
Massachusetts Air Pollution Regulations explicitly disallow
construction as a means of achieving high occupancy vehicle lanes
on the most heavily traveled section of Interstate 93 north of

HOV lanes can also have a serious impact on land use patterns.
Because the lanes temporarily make commuting easier and quicker,
their availability encourages housing and job choic- 

A Report by the CHESAPEAKE BAY FOUNDATION                         11

es that require long commutes. Since time matters more than
distance to most commuters, sprawl growth is promoted by the
increased general capacity and (temporarily) lessened roadway
congestion that follow new HOV lane construction. Areas of urban
sprawl generate more motor vehicle trips than traditional cities,
and are more difficult to serve by transit [Relogle].

Computer models have been designed to determine how HOV lane
construction in the Sacramento area would affect where people live
and their mode of transportation, as well as where and how often
the travel. The models show that by the year 2010 carbon monoxide
levels would be little better, and oxides of nitrogen levels would
actually be worse than if the HOV lanes were not constructed. In
the long run, the air quality results would almost certainly be
much worse [Johnston; Johnston and Ceerla]. the name of air quality, HOV lane construction could
     lead us farther from that goal.

Even though they are being justified on the basis of claims of air
quality benefits, many proposed HOV lane construction projects are
escaping close environmental examination. It seems obvious that
projects this magnitude ought to be required to file a federal
environmental impact statement, although many have not. Careful
analysis of air quality impacts and alternatives should precede any
effort to: (1) classify an HOV lane construction project as a
transportation control measure; (2) fund HOV construction with
federal Congestion Mitigation and Air Quality (CMAQ) funds; or (3)
find construction of an HOV lane in conformity with federal clean
air requirements.

Under the Clean Air Act, transportation control measures must not
increase single occupancy vehicle capacity. Since new HOV lane
construction undeniably does, it is difficult to see how this
construction can be listed as a transportation control measure. And
since under ISTEA, federal funds to increase single occupancy
vehicle capacity cannot be spent in a nonattainment area unless all
alternatives have been considered, new HOV lane construction should
not be approved in those regional plans and funding programs.

Air quality regulators need to be vigilant; in the name of air
quality, HOV lane construction could lead us farther from that
goal. They should be particularly skeptical of construction that
will designate the new lanes as HOV only at peak periods. It is
difficult to understand why, during periods of non-peak traffic
volumes, single occupancy vehicles would need access to lanes that
the HOVs had used during peak periods. In approving a transit or
HOV facilities without guarantees that it will remain so, the
regulators are quite likely in the long run to get a general
purpose facility that they never intended. In congested urban
areas, FHWA, EPA, and state and regional air quality regulators
should be hesitant to approve automobile lane construction.

As discussed in a later section, converting general purpose lanes
to HOV use can more effectively reduce long-run driving and
encourage carpooling and transit. Possible short-ten-n carbon
monoxide problems are sometimes held against the conversion
alternative, even though it would do most in the long run to reduce
carbon monoxide, ozone precursors and other air pollutants.

12                                                    ReThinking HOV


RECOMMENDATION 8: A car with two occupants is low occupancy, not
high, and should not be encouraged by new construction. If 2+ is
adopted as a minimum occupancy level for HOV existing lanes, that
status should be conditional. The lane should be upgraded based on
performance or on an automatic schedule for higher occupancy or
bus-only status.

What constitutes a truly high occupancy vehicle? Mr. Henry Bain is
a consultant in urban transportation and community development with
over 30 years of experience. In a letter to the authors, Mr. Bain
observes: "Suppose, before HOV became a popular term, we had shown
someone a chart displaying the full range of vehicles using the
highways, from a driver-only automobile to a large, full bus, and
asked which point separated vehicles with a high occupancy from the
rest. Would anyone, facing such a choice, have picked four, much
less three or two?" Yet much of the recent debate has focused on
whether the number should be four, three, or two.

Buses were once considered the real high occupancy vehicles; and in
some places, such as Ottawa, they still are. But as HOV has been
redefined, vehicles carrying four, three, and now as few as two
people are considered high occupancy. HOV lanes that for years were
operated exclusively for buses or for 3+ carpools are now being
downgraded to 2+. It is almost Orwellian to use the term "high
occupancy" to refer to a vehicle with only two occupants,
especially when four or more could be comfortably accommodated.

The weakening of the HOV concept is exemplified by Houston's Katy
Freeway (I-10) "transitway." Opened in October 1984, these lanes
were constructed solely for buses and authorized vanpools. Only six
months later, 4+ carpools were added, and seven months after that,
3+ carpools were added. Then in August 1986-less than two years
after opening these lanes (and Houston's other transitways) were
opened to carpools with only two occupants. These changes severely
compromised the speed and safety of the buses and vanpools for
which the transitways were originally built. In a similar story,
lanes built exclusively for buses have been opened up to carpools
on Virginia's Shirley Highway (1975) and the San Bernardino Freeway

An evaluation of the Seattle area's downgrade from 3+ to 2+ shows a
large increase in vehicles in the HOV lanes without a significant
reduction of vehicles in the general purpose lanes [Ulberg, 1992].
In fact, there was a decrease in the freeway's overall vehicle
occupancy and an increase in the proportion of single occupancy
vehicles (SOVs). People left buses (now slowed by the traffic) for
carpools and left vanpools and larger carpools for 2+ carpools.
They also shifted onto the freeway from parallel arterials, and
traveled more at peak periods. And they took trips that formerly
they would have not made at all. Collisions also increased. These
results did not move Washington state to return the lanes to 3+.
However, they did occasion a performance standard suggesting the
return to 3+ if vehicles in an HOV lane cannot maintain a 45 mile-
per-hour speed during 90 percent of weekday peak hours.

An argument sometimes made in favor of a 2+ minimum occupancy
requirement is that it is a way to avoid the "empty lane syndrome."
In the early years of an HOV project, people are slow to form 3+
carpools or begin taking the

A Report by the CHESAPEAKE BAY FOUNDATION                         13

bus, causing an HOV lane to seem underutilized. The relative lack
of vehicles in an HOV lane despite the large number of people
served by it-attracts pressure from other drivers to open it up to
single occupancy vehicle traffic. Thus the 2+ designation is
tempting as a way to protect the lane's HOV designation until
enough 3+ carpools join the buses to make it look "full."

But is 2+ a reliable route toward higher occupancies? Opening the
HOV lane to 2+ carpools eliminates any additional incentive to form
or maintain 3+ carpools. If the 2+ designation floods the HOV lane
and reduces its time advantage, the advantage for carpools over the
general purpose lanes will be inconsequential. And although
sufficient 3+ carpools may become available, or there may be
sufficient hope of them to justify establishing a 3+ lane, once the
2+ designation has been adopted it will be politically difficult to
restore the lane to a 3+ status. Elected officials find it
difficult to deny the 2+ carpoolers their newfound privilege,
especially as many of the 3+ carpools that would benefit are not
yet formed. The resistance to later attempts to institute 3+ or
higher occupancies suggests that the 2+ standard is not
encouraging, real changes in behavior, and may make it all the
harder to encourage 3+ carpoolers and protect transit service in
the long run.

The counter argument is that when a 2+ minimum begins to degrade
the performance of an HOV lane, it can be, raised again to 3+ or
higher. And in fact, there is at least one successful example, the
restoration of 3+ on Houston's Katy Freeway (peak-period only; at
other periods 2+ still applies). However, that change was long
delayed, and has not been extended to other worthy HOV lanes in
Houston and around the country. In general, the direction of change
everywhere is toward the lowest possible carpool minimum, two.

A situation where selecting 2+ rather than a higher minimum
occupancy might be justifiable is in the initial years when an HOV
lane has been converted from general purpose use. In the 1970s the
conversions on the Santa Monica Freeway and Boston's Southeast
Expressway might have survived if they had been 2+ instead of 3+.
The 2+ minimum would moderate additional congestion experienced in
the remaining general purpose lanes.

But in no case should a 2+ minimum occupancy be allowed to clog the
HOV lane. A study of the possible conversion of a lane on I-93
north of Boston found that only a 3+ designation would assure
carpools and buses peakperiod speeds significantly more favorable
than on the general purpose lanes [Massachusetts Highway
Department, p. 191. Although at 3+ the lane would be sufficiently
free-flowing to appear "empty" to the envious driver in a nearby
lane, it would carry more people than any of the other lanes.

In the future, a 2+ occupancy minimum should be adopted only under
very specific conditions and deadlines, specifying when a 3+ or
higher definition will be adopted.

14                                                    ReThinking HOV


RECOMMENDATION 9: States with poor HOV lane enforcement records
should have to return part of the federal funds used to construct
the lanes, and should have a harder time qualifying for future HOV
lane construction funds.

The advantages of HOV lanes are lost if solo drivers use the lanes.
Some HOV lanes receive so much illegal single-occupancy vehicle
traffic as to be HOV almost in name only. Florida's Department of
Highways reports peak-hour violation rates of 75 percent on I-4 in
Orlando and 40 percent on I-95 in Miami, a virtually complete
breakdown in enforcement. Other examples of high violation rates
are on HOV lanes on Virginia's I-66 (45 percent) and I-95 (55
percent), Houston's Katy Transitway (35 percent), New Jersey's I-95
(30 percent), and I-5 south of Seattle (30 percent) and north of
Seattle (19 percent) [Tumbull and Hanks; Lomax and Fuhs;
Farnsworth]. Violation levels in many areas would be higher, but
the general purpose lanes are often uncongested enough that solo
drivers are not tempted by the HOV lanes.

Even though many jurisdictions are strengthening enforcement, fines
are not high enough and enforcement is not stringent enough to stop
solo drivers from clogging HOV lanes. States are required to give
back federal welfare funds if they allow unreasonable levels of
welfare fraud; why should they not also give back a portion of
federal construction funds if HOV lanes are not being used as

The trend toward allowing general purpose traffic on HOV lanes in
non-peak periods is increasing the accident and enforcement prob-
lem. Lanes that are HOV only at peak period offer an opportunity
for some drivers to sincerely or insincerely plead confusion. In
response to proposals to open up Orange County's 24-hour HOV lanes
to general purpose traffic in non-peak periods, the California
Highway Patrol wrote that 24-hour HOV status is "less confusing to
the public, generally safer to operate, and easier to enforce"
[Orange County Transportation Authority].

The easiest way to reduce enforcement and collision problems is to
limit the number of carpools. If a lane is designated bus-only
rather than simply HOV, fewer solo drivers will violate it. Bus-
only lanes have almost no violations when separated by barriers
from surrounding traffic, and a minimal amount when these barriers
are absent. Bus lanes also have lower accident rates than general
purpose lanes, whereas HOV lanes have higher accident rates than
general purpose lanes. In general, buses (which have professional
drivers) are much safer than automobiles.

Enforcement and collision problems are sometimes cited to justify
constructing new, barrier separated lanes, and to argue against
lane conversions or for opening up "substandard" HOV lanes to
general purpose traffic. Separating the HOV lanes does aid enforce-
ment and discourages solo drivers (SOVS) from treating them as
"shoulders." The lack of buffers and enforcement areas often
reflects an unwillingness by authorities to take away roadway space
from traffic. When this space is genuinely unavailable, an HOV lane
at least can be semi-separated by a few feet of buffer, greater
marking of the pavement, rubber pylons or other engineering
techniques. Especially effective are signs in California that
mention a $271 fine for violators!

A Report by the CHESAPEAKE BAY FOUNDATION                        15 


RECOMMENDATION 10: To help prevent backsliding, peak-period HOV
lanes should be extended to 24-hour operation. Existing 24-hour HOV
lanes should remain so.

Will new HOV lanes be HOV for long? Whether before or after their
opening, several HOV lanes around the country have been opened to
general purpose traffic. HOV lanes built for Atlanta's I-75 and I-
85 were opened in the 1970s as general purpose lanes. California
freeway lanes planned for HOV that were later opened to general
purpose traffic include parts of I-580 in the San Francisco Bay
area, the San Diego Freeway (I-5), the Ventura Freeway (US- 101 ),
and the Long Beach-Artesia Freeway.

When a nine-mile stretch of Virginia's SR-44 was opened with a peak
period HOV lane in 1986, the state legislature forced the lane's
reclassification to 24-hour general purpose traffic. Although the
state permitted a return to HOV after 1990, this change was not
made until September 1992, and then only for a five-mile stretch,
and for 2+ carpools rather than the 3+ that had originally been
planned. Meanwhile, the Route 44 shoulder was improved to allow
general purpose traffic during peak hours. During peak period HOV
restriction, the highway has two more general purpose lanes than
originally planned. Planners and air quality regulators cannot be
proud of that result.

One of the quickest backslides was on the newly constructed HOV
lanes on Virginia's Dulles Toll Road; these lanes were opened up to
general purpose traffic after only a month of HOV operation. Built
between the existing Dulles lanes on a median that had been offi-
cially set aside for transit use, the new lanes were nevertheless
opened to general purpose traffic on an "Interim" basis as segments
were completed. The 12-mile length was dedicated in 1992 as a 24-
hour HOV facility with a 3+ requirement, and it had substantial
use. It was an election year, however, and opponents persuaded the
Virginia Department of Transportation to consider and then adopt
general purpose use. The same Congress that the year before had
passed ISTEA as a means to promote transportation alternatives and
strengthen local prerogatives capitulated to political pressure and
forced the new HOV lanes to general purpose use. Although the
change was initially portrayed as an "interim" measure, it seems
unlikely that the HOV lanes will be restored any time soon

Even agreements negotiated amid great public controversy have later
failed to assure

ClickHERE for graphic.

16                                                    ReThinking HOV

promised HOV designations. Upon their construction in 1977, the I-
580 lanes were, designated HOV as a result of a Sierra Club law-
suit; then over Sierra Club protests, Caltrans opened them in 1982
to general purpose traffic. The strong opposition to construction
of a ten-mile section of I-66 into downtown Washington, D.C., was
overcome in the early 1970s through an agreement allowing access at
the peak period only to buses, 4+ carpools, and vehicles going to
and from Dulles Airport. But only a year after the new lanes were
opened, federal legislation (Public Law 98-105), in a provision
applying specifically to this highway, reduced the minimum carpool
size to 3+ and shortened the peak period in which restrictions
would apply.

Regarding I-90 east of Seattle, a 1976 agreement (between the
Washington State Department of Transportation, King County and
Metro transit, and the cities of Seattle, Bellevue, and Mercer
Island) required transit lanes in both directions between Seattle
and Bellevue, with the direction of minor flow reserved for buses.
However, in 1987-without consulting the public interest groups that
had fought for the lanes-these parties decided to make the lanes
only one direction during peak periods.

As the Dulles case shows, it is risky for the future of HOV lanes
to admit general purpose traffic to a future HOV lane segment,
whatever the appeal of making some use of it in the interim before
connections to other HOV lanes have been established. Once having
used the HOV lanes, solo drivers come to see the lanes as their
property. The future of HOV lanes is also threatened by allowing
general purpose traffic on them during offpeak periods. In some
parts of the country, newly constructed HOV lanes have from the
start been HOV in the peak period only; in other cases (such as the
Shirley Highway "busway" since 1985), 24-hour HOV lanes have later
been opened to general purpose traffic in nonpeak periods. When
drivers get used to off-peak access to the lanes, they are more
skeptical of requirements for busonly, 4+, or 3+ even at peak

With the addition of passenger rail lines, there is an unfortunate
temptation to open parallel HOV lanes to general purpose use,
rather than retain them for short-haul buses, vanpools, carpools,
and emergency vehicles. Elimination of a bus-only lane is made more
difficult if the lane is designed specifically for buses and will
not easily accommodate automobiles. Keeping Ottawa's and
Pittsburgh's lanes as bus-only has been assisted by their design,
which clearly separates the lanes from surrounding traffic and
connects the lanes with on-line stations.

RECOMMENDATION 11: Federal or state funding of HOV lanes should be
with a "money-back guarantee" requiring return of the funds if the
HOV lanes are subsequently changed to general purpose lanes.

Much of the backsliding to general purpose lanes mentioned here
occurred where federal funding was specifically for HOV lanes.
Funding agencies have been very permissive of this drift away from
the funding purposes. Federal laws and regulations, and the
contracts and other agreements under which funds are conveyed
should be strengthened to prevent this problem in the future.
Otherwise, the laws, regulations, and agreements could be actively
thwarted by subsequent events.

A Report by the CHESAPEAKE BAY FOUNDATION                         17

RECOMMENDATION 12: Do not impose vehicle-flow requirements on HOV
or bus-only lanes when people-carrying capacity is the more
relevant criterion.

It is unfortunate that minimum vehicle thresholds for volume of HOV
travel are-formally or informally-being imposed as a condition for
reserving some lanes for buses, vanpools, and carpools. In southern
California a lane may have to assure 750 to 800 vehicles per hour,
and in the Seattle area 400 to 450 vehicles per hour [Fuhs, 1993,
p. 20]. The effect is to impose on transit and HOV lane planning a
vehicle-flow standard that is more appropriate for general purpose
lanes. A more relevant standard would be how many people are being
carried on the lane.

New Jersey's bus-only lane on I-495 into the Lincoln Tunnel for
many years admitted no more than 500 vehicles per hour-even though
carrying (as it still does) more people in that hour than any other
lane in the nation. Even on HOV lanes where the number of people
carried may initially be less than on the adjacent general purpose
lanes, HOV status may be justified by the public interest in
facilitating transit and a long-range effort to build vanpools and


RECOMMENDATION 13: Bus-only and HOV lanes should be established
first by conversion from existing general purpose roadways. New
lane construction should be a second choice, if it is chosen at
all. No lane that is HOV at peak periods only should be
constructed; such lanes should be established only by conversion.

Given the drawbacks and expense of HOV lane construction, it makes
sense to establish HOV lanes by conversion of existing general
purpose lanes. In fact, most bus-only lanes now in existence-and
there are thousands around the world-were conversions from traffic
or parking lanes [Turner]. Conversions to bus-only of all or parts
of entire streets that were formerly in general purpose use include
Nicollet Mall in Minneapolis, the Transit Mall in Portland
(Oregon), Denver's 16th Street Mall, Honolulu's Hotel Street Mall,
and Chicago's State Street Transit Mall. More common are bus-only
lane conversions, some limited to peak periods. A major Caltrans
office in Los Angeles is located on Spring Street, which since 1974
has had a 24-hour bus-only lane. Many of the continent's other
large cities have bus-only lanes, as well as smaller cities such as
Ann Arbor, Harrisburg, Hartford, Indianapolis, Louisville, Madison,
Providence, Rochester, and Tucson.

Freeway lanes, too, have been converted for bus or carpool use.
Successful conversions for peak-period bus travel include the
contraflow bus lanes on I-495 eastward into the Lincoln Tunnel
(1970) and westward into the Queens

18                                                    ReThinking HOV

Midtown Tunnel (1971); a contraflow bus lane on I-278 (the Gowanus
Expressway) into the Battery Tunnel; and in Colorado eastbound on
U.S. 36 (the Boulder Turnpike). Other lane conversions now in use
by buses and carpools include a bus lane (1970) and two carpool
lanes (1971) on I-80 on the eastern approach to the San Francisco-
Oakland Bay Bridge; SR 676 on and near Philadelphia's Benjamin
Franklin Bridge; Honolulu's Kalanianaole Highway; and Route 10 on
and near Montreal's Champlain Bridge. In 1975, a lane conversion to
create a contraflow bus lane on U.S. 101 in Marin County occasioned
a net reduction in general purpose capacity, which was restored in
1983 as a result of new construction.

Despite its commonality in practice, the conversion alternative has
often been ignored or too readily dismissed in technical studies.
Some state highway departments prohibit conversion outright or
impose tighter preconditions and analytical requirements than they
do for construction projects. Some official analyses even state
that, nationally or locally, conversions have not been done. For
example, consider the following statement from a 1992 study,
"Experience with 'take-a-lane' actions is quite limited, largely
because of the failure of the first and only attempt to take a
general purpose lane for use as an HOV lane, a 1976 demonstration
project on the Santa Monica Freeway. Locally, there have been no
take-a-lane actions, but the take-a-lane option was considered for
the Pacific Street HOV Project and has been studied for the I-5
South Interim HOV Project. [Parsons Brinckerhoff] Benefit-cost
studies [such as Ulberg and Jacobson, 1987] compare HOV
construction with the construction of general purpose lanes,
without analyzing the alternative of converting an existing general
purpose lane. The result is to ignore the high initial and
recurring budget costs of the new roadway, as well as its initial
and recurring nonbudget costs such as community and environmental

In some cases (such as on I-5 south of Seattle), the Federal
Highway Administration has not insisted on an environmental impact
statement for HOV lane construction, while saying an EIS would be
required for creating the same lanes by conversion. And FHWA has
usually failed to require alternatives analyses and major
investments analyses to give serious consideration to conversion.
This is in spite of the fact that ISTEA and the National
Environmental Policy Act both require that proposed construction be
compared with less expensive, lower impact, and nonstructural
alternatives [USDOT].

In many cases, experts are not providing policymakers detailed
analysis of the conversion alternative. It does not seem
appropriate for transportation professionals to make political
judgments about which alternatives to exclude from the public
agenda. Elected leaders and the public need all the options and a
comparison of their actual, long-run impacts. National debate
regarding proposals for HOV lane construction has not been well
served by public agencies dependence on a few consulting firms and
university institutes. Land use planners, social scientists,
transit experts, and others have important perspectives on whether
to construct a new HOV lane.

A full range of perspectives should be assembled when public
officials are presented with transportation alternatives. Reports
and conferences sponsored by the Transportation Research Board's
Committee on HOV Systems need to better evaluate the costs and
benefits of constructing new HOV lanes and more fully consider the
conversion alternative.

A Report by the CHESAPEAKE BAY FOUNDATION                         19

The National Research Council, of which the Board is a part, should
insist that a wide range of views be represented on its committees
and in their products.

In the rare efforts to analyze the conversion alternative, it
generally has not received the careful analysis that policy makers
deserve. Analyses often use the alarming term "take-a-lane," and
sometimes even "take-away" a lane [Parsons Brinckerhoff;
Bechtel/Parsons Brinckerhoff]. They might as well call it "steal-a-
lane;" it is as if general purpose were the highest and best use.
Official use of the term take-a-lane and claims that it is "rarely
applied" should be dropped [see glossary in Fuhs, 1993]. The more
neutral term "lane conversion" should be employed.

It is true that more than a decade ago a few conversions of general
purpose lanes to HOV were later reversed, but the wrong lessons
have been drawn from these cases. In California and elsewhere, the
controversy over the Santa Monica Freeway HOV lanes has often been
invoked as reason enough not to try a lane conversion. But that
experience was unique: it occurred nearly two decades ago, before
many drivers had heard of an HOV lane; southern California drivers
are hardly typical of those in other parts of the country, and
Caltrans did not manage or market the conversion successfully.
Looking back on the 21 week experiment with HOV lanes on the Santa
Monica Freeway (I-10) in 1976, a Caltrans official now judges that
"we did almost everything wrong" [Baxter, 1994]. Ironically, the
experiment did succeed at a number of its immediate goals. The
Santa Monica Freeway HOV lanes carried nearly as many people as the
other lanes combined, and helped the freeway carry more people in
fewer vehicles than any time before or since the experiment.
Carpools and bus ridership more than tripled and were increasing
further, although they dropped when the lane was discontinued. Air
quality appeared to be improving during the period of conversion.
[Billheimer et al; SCRTD].

All but forgotten is Caltrans' success-before, during, and after
the conversion and revocation of the 1976 HOV lane-in converting
lanes on ramps connected to the Santa Monica Freeway itself.
Evaluators found that during the period of the demonstration
project, the converted HOV bypass lanes, in combination with the
timing of the ramp meters to which general purpose traffic was
subject, gave more time savings to HOVs than did the converted
freeway lanes themselves [Billheimer, et al]. This successful
experience led to the creation of hundreds of queue bypass lanes-
often by the conversion from general purpose lanes on freeway ramps
all over southern California.

The January 1994 Northridge earthquake occasioned further lane
conversions on the Santa Monica Freeway. When part of the freeway
became impassable, Caltrans designated a five-mile exclusive lane
on the freeway between La Brea and Overland for exclusive use by
buses, vanpools, and carpools. Non-HOVs were not allowed on the
freeway and used a longer detour on city streets, giving a fifteen
minute time advantage to the HOV lane users. Despite entreaties
from city, county, and transit officials, Caltrans resisted pro-
posals to make the conversion permanent once repairs on the freeway
were completed. An eight-mile temporary shortcut for buses and HOVs
was also established on I-14; this conversion too was not expected
to survive once repairs reopened the freeway. Similar lane
conversions to HOV were accomplished after the 1989 Loma Prieta
earthquake in the Bay area; these too did not survive once repairs
were completed [Auslam].

20                                                    ReThinking HOV

It did not take an earthquake for the Washington State Department
of Transportation to convert a general purpose lane in November
1993. A lane of I-90 (9.4 lane miles) was converted westbound to
24-hour HOV (the eastbound section is scheduled to be converted in
connection with a future resurfacing project). The converted lane
connects with a recently constructed HOV lane running west to
Seattle and cost only $ 100,000. Newly constructed lanes would have
cost $70 million and were not scheduled until after the turn of the
century. In the peak hour, the converted HOV lanes were carrying
about 350 vehicles in 1994-considerably below the threshold that
some regard as subject to "empty lane syndrome"-yet there has been
little public resistance to the change.

In 1994 the New Jersey Department of Transportation was successful
in converting five miles of general purpose lanes on I-80 to HOV.
These lanes had been constructed for HOV use but were opened up to
general purpose traffic until connections were available to other
HOV lanes. The conversion was eased by a long period of marketing
that included highway signs informing drivers that lanes were
scheduled to become HOV [Fisher, 19941. A similar successful
conversion of general purpose lanes that were originally built for
HOV was accomplished in 1989 on Route 91 near Corona in Southern
California [Auslam].

Too often, lane conversion is discounted because it "can't be done"
or "hasn't been done." It can be and has been done all over the
world; but even if not, why not try? Highway planners once dreamed
great dreams; why do they suddenly lose heart when contemplating
the opposition of some drivers to more efficient use of existing
roads? Converting general purpose facilities to HOV or bus-only use
should be regarded as a challenge, to be addressed with the same
professionalism that engineers use for construction projects.

Research shows that the public often is more supportive of lane
conversion than are government officials and the experts they

Research shows that the public often is more supportive of lane
conversion than are government officials and the experts they
employ. In the largest opinion survey yet done on lane conversion,
a 1993

study of adults in the Los Angeles, San Diego, and San Francisco
Bay areas found substantial support for lane conversion to HOV
[Gard et al.]. As many preferred lane conversion as preferred lane
construction as a means toward HOV lanes. Many of those who
preferred construction also were willing to support conversion (two
thirds would support lane conversion if it were to complete an HOV
lane network). A similar 1994 survey of adults in the Sacramento
area produced similar results; in fact 88 percent supported
conversion of a lane in each direction even on a freeway with only
four lanes. In both surveys, reasons for preferring conversion over
construction included cost, construction-related traffic con-
gestion, and the need to more quickly connect existing HOV lanes
[Gard et al.].

The standard objection to conversion-that near-term congestion
could increase in the remaining general-purpose lanes-should not
end discussion. Without lane conversion, increased congestion is
forecast for most urban areas-all the more reason for an active
effort to limit its effects by establishing a net-

A Report by the CHESAPEAKE BAY FOUNDATION                        21 

work of HOV lanes soon by lane conversion.

Additional steps can also mitigate or prevent worsened congestion
from a conversion. Toronto's Department of Public Works and the
Environment showed imagination in implementing the Bay Street Urban
Clearway. The addition of turn restrictions at a number of
intersections and the prohibition of stopping at curbside actually
increased the volume of general-purpose traffic and reduced the
levels of congestion on Bay Street [Toronto]. Traffic engineering
is being used in a similarly creative way to assure that a
conversion project on Montreal's Bonaventure Highway does not
increase congestion. A 1.5 mile conversion to HOV of a general
purpose lane on the main stem of Washington's I-5 through downtown
Seattle was made more palatable by the creation of an additional
general purpose lane by restriping a parallel collector-distributor
stem of the freeway.

To many people, the origin of the HOV lane is less relevant than
how well it works. In researching this paper, the authors found
that even transportation agency professionals were hazy about
whether one or another HOV project had converted a traffic or
parking lane, was squeezed in by restriping the roadway, or stemmed
from new lane construction on a shoulder or median.

Pressure to allow general purpose traffic seems as strong on those
HOV lanes that were created by construction as on those that were
created by conversion. In fact, more HOV lane mileage created by
construction has suffered backsliding to general purpose use than
has the HOV lane mileage that was created by conversion. The fact
that all HOV lanes-constructed and converted alike-are under
pressure to allow general purpose traffic is a reason to discourage
the construction alternative.

Lane conversion is particularly attractive as a means to connect
existing stretches of HOV lanes. Waiting years or decades for new
construction has been disastrous for connectivity; conversions
should be aggressively implemented even if later construction is

Lane conversions have been successful in minimizing the traffic
tie-ups inflicted by major events, and it is surprising that they
are not done more frequently. An outstanding example (begun in
1960) is the conversion of general purpose lanes to a bus and taxi-
only lane on Chicago's Lake Shore Drive for three hours before
football games, rock concerts, and other major events at Soldiers'
Field. The 1984 Los Angeles Olympics occasioned major temporary
conversions. A number of freeway ramps (including several on the
Santa Monica Freeway), as well as lanes on major arterials, were
made bus-only. This measure-part of an ambitious effort to
discourage driving helped buses account for an impressive 45
percent of those attending events at the central Coliseum area.
During the Olympics, the Los Angeles area experienced less
congestion than it does normally and avoided the traffic tie-ups
that, before and since, have been typical of major events there. An
evaluation of the busonly lanes and other changes in the road net-
work found that "the small negative impact on regular traffic was
more than offset by benefits of the transit service" [Giuliani, p.
133]. Whereas the conversions adopted during the Los Angeles
Olympics did not continue afterward, the permanent conversion to
HOV of 58 miles of general-purpose lanes on I-75 and I-85 is now
being planned to help Atlanta cope with traffic from the 1996

22                                                    ReThinking HOV

RECOMMENDATION 14, Urban areas should establish contingency plans
for the conversion of general purpose lanes to exclusive HOV or
transit use in the event of an energy shortage, a disaster, or
nonattainment of clean air standards.

Crises are an opportunity to experiment with a higher use for the
public roadways. In the days, after the sinking of an I-90 bridge
over Lake Washington, the Washington State Department of
Transportation was urged to convert lanes on a temporary basis to
high occupancy or transit use on the remaining two bridges and on
nearby freeways. The department had no contingency plans for such
conversion and resisted even discussing the idea. As mentioned
previously, Caltrans was more creative in instituting conversions
after the Loma Prieta and Northridge earthquakes, but was not
receptive to keeping the new HOV lanes after earthquake repairs
were completed.

The contingency plans that must be included in all state
Implementation plans (SIPS) under the federal Clean Air Act are an
appropriate place to include the conversion of general purpose
lanes to HOV and bus-only. The contingency measures are to be
implemented if the SIP fails to bring the area into attainment with
federal clean air standards

RECOMMENDATION 15: Highway design manuals, road fund programming
guidelines, transportation laws and plans, and other guidance
should require study of the conversion to HOV of general purpose
lanes as the prime alternative when any construction of new general
purpose or HOV lanes is being considered.

Sooner or later, large-scale conversion of general purpose lanes to
HOV use as a way to more efficiently use our public roadways seems
inevitable. Projected traffic volumes are increasing far beyond
what can be accommodated by any foreseeable construction of new
lanes. Unfortunately, we are missing the window of time when
conversion would be easiest, and when transit and ridesharing could
most use the boost. Conversion of a general purpose lane is most
difficult once that lane has become congested, and when solo
drivers have come to regard it as their own. In all lane
conversions, there must be an accompanying public information and
public relations program that is carefully planned and executed.
Building bus ridership and carpooling, takes time. A policy to seek
conversions early and support them with well-funded public
relations campaigns is the most far-sighted approach.

RECOMMENDATION 16: Conversion to HOV from general purpose lanes
should always be preferred to "take-a-rail."

Much as the street cars were sacrificed to pave more automobile
lanes earlier in the century, some HOV lanes are being created on
right -of -way that was formerly for passenger rail or that is
intended for future use by passenger rail. One remarkable proposal
for an HOV lane on I-93 would close tracks now used by Boston's
Braintree branch of the Red Line, forcing an extra stop and
increasing, travel time for rail passengers [Bechtel /Parsons
Brinckerhoff]. To achieve HOV lanes by setting back trains-the
ultimate high occupancy vehicle- is to forget under which
conditions the lanes can be justified. Rather than "take-a rail,"
conversion of existing general purpose lanes to HOV should be
particularly emphasized.

A Report by the CHESAPEAKE BAY FOUNDATION                         23

IX.  Beyond the high occupancy vehicle

High occupancy vehicle lane construction has failed to live up to
its professed goals of promoting transit, reducing the mileage
driven, lessening air pollution, and promoting more efficient land
use. The foregoing recommendations-among them, to create HOV lanes
mainly by conversion from general purpose lanes, and to limit new
construction to transit and emergency lanes-would help to salvage
the concept of preferential access. However, continued pressure to
build more HOV capacity and then allowing non-HOV use suggests the
need for a reconsideration of the idea of giving preference to


Debates over HOV lanes have begun with the assumption that major
new roadway capacity is to be constructed. Once it is assumed that
more roadway lanes are to be added, of course it would be better
for these to be HOV lanes than general-purpose lanes. But these
debates fail to consider whether the construction itself is needed.

Prior to the 1970s, the fields of electric power and solid waste
planning had a similar bias for new capital facilities to supply
more power and disposal capacity. However, in a major shift, these
fields have come to recognize that maximizing the efficiency of
existing facilities and managing demand are more important than
expansion. For example, the concept of "least cost planning" has
revolutionized the electric power field. Recognizing that demand is
uncertain but will increase quickly if supply is subsidized,
planners now explore all options, including nonstructural ones, and
consider their full costs, including social and environmental costs
[Steiner; Sheets and Watson; Nelson and Shakow].

In power planning, the quickest and most inexpensive way to
increase "supply" has been to manage demand. Expensive new
facilities for peak demand-in fact, overbuilding for demands that
never materialize-could be avoided through conservation, peak
spreading, and pricing. The least cost perspective encouraged
examination of overlooked resources such as co-generation and small
sources. In some locales electric utilities have even encouraged
peak-demand clients to shift to nonelectricity modes. Some
customers are also agreeing to allow their utility to ration their
supply of electricity.

Just as least-cost planning was pushed along by the concern over
the environmental costs of nuclear and coal power generation, the
recycling movement was pushed along by the threat of massive
garbage incineration and toxic landfills. Recycling compels
consumers to pay attention to what they consume and to sort their
waste for further processing. By bringing attention to the large
amount of nonrecyclable waste, it focuses attention on waste
reduction and reuse. Thus it increases the visibility of
externalities (costs-such as for pollution-that once were quietly
passed on to others or the environment) and internalizes them as
direct costs.

These successful movements in energy and solid waste suggest some
obvious parallels for transportation planning. Capital facilities
are costly to site, build, and maintain. This is especially true
for transportation, which is society's largest single public
investment, even aside from costs to the environment from pollution
and sprawl, and to the communities plagued by traffic and urban
flight. Building new lanes is extremely expensive and imposes
recurring costs for maintenance and enforcement. In

24                                                    ReThinking HOV

most cases, it would be useful to examine whether the funds going
into HOV construction would be better spent in other ways.

An alternative to supplying more room to drive and park is to use
existing facilities more efficiently, and find ways to moderate
demand. Current policies allow the least efficient users-single-
occupancy vehicles-as much access to most lanes as fully loaded
vehicles, and without making any distinction as to whether the trip
could have been avoided. In the same spirit as recycling, we need
to sort trips and set priorities among them. HOV lanes are the
beginning of an effort to sort trips, but in most cases the
distinctions have been too blurry and the priorities have not been

An alternative to supplying more room to drive and park is to use
existing facilities more efficiently and find ways to moderate

The most effective means of waste reduction is to eliminate a need
entirely. In the same sense, trips can be eliminated if people
telecommute or live closer to where they work. Public subsidies,
zoning, and other means to encourage urban design and land use
consistent with these choices could more permanently and cost-
effectively address transportation needs than a vain effort to
build our way out of burgeoning demand. Public works spending
should be redirected into traffic calming (measures that slow motor
vehicles to enable sharing of the road with transit and nonmotor-
ized uses), pedestrian and bicycle improvements, public transit,
and other measures that increase efficiency and cause some automo-
bile trips to disappear [Roberts].


The attractiveness of HOV lanes stems significantly from the
terribly inefficient management of our general purpose lanes.
Society does not benefit when the public roadways are so clogged as
to daunt any user. If pricing, permits, or other methods could be
used to prevent the overloading of the general purpose lanes, the
very need for separate HOV lanes-or any other preferential access
would greatly diminish.

Pricing is society's most common and effective way to allocate
scarce goods among competing priorities. If the nation's long-
distance telephone lines were free, they'd be jammed, too. But
phone companies not only charge users; the price is higher at peak
periods, so the system rarely gets overloaded. If prices for road
and bridge access and for parking better reflected the societal
cost of the driving decision, congestion would be much less
[Johnson]. Toll booths are beginning to be replaced by automated
and remote sensor toll collection as a means to reduce delay and
vary rates based on the time of day.

The HOV concept's emphasis on people-carrying capacity does not
address society's interest in assuring the delivery of goods and
services. Heavy trucks currently share peak period access with HOVs
to the Sterling Street on-ramp eastbound toward the San Francisco-
Oakland Bay Bridge, but they pay no premium for this privilege.
Heavy trucks cause more than their share of incidents and
accidents, road damage, air and water pollution, collisions, and
traffic congestion. Trucks now pay only a small proportion of these
costs; giving them free access to the HOV lanes would further skew
the incentives, and could reduce the safety of other users of these
lanes. Only if trucks were charged hefty

A Report by the CHESAPEAKE BAY FOUNDATION                         25

fees would it seem reasonable to grant them access to the HOV

Proposals are increasing to admit general purpose traffic to HOV
lanes at the price of a toll. We suggest strong resistance to these
proposals. Tolls should be placed on the general purpose lanes. To
admit general purpose traffic to HOV lanes would reduce the time
advantage enjoyed by users, and would undermine the public utility
image of the lanes. To protect their special status, we suggest
that the lanes be officially designated as transit and emergency


HOV lane construction should not be just a new way to get highway
expansions past regulators or budgeters. Exclusive lanes should be
built for buses and emergency vehicles. If carpools are to be
allowed on these lanes, they should be fully loaded and certified
as priority trips. Some inconvenience to cars with one or two
occupants is in many cases desirable to induce increased car
occupancies and transit use.

HOV lanes alone cannot correct the current mismatch of incentives
and impacts that cause wasteful levels of driving. A more rational
system of prices, coupled with better land planning and wiser
public investments would reduce the need for more roadway expansion
and would help preserve a transit and emergency lane as a modest
but important part of the solution. The stakes-healthful air, sound
urban design, energy conservation, efficient use of scarce
transportation dollars-are too high not to rethink our policy on
high occupancy vehicles.

26                                                    ReThinking HOV


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A Report by the CHESAPEAKE BAY FOUNDATION                         27

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28                                                    ReThinking HOV

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