Appendix D.
Prior Research on Infrared Brake Screening Technology for CMVs
This appendix comprises a short summary of the USDOT (2000) study conducted to evaluate infrared brake screening technology. The full report is available online at: http://www.itsdocs.fhwa.dot.gov//JPODOCS/REPTS_TE//13339.pdf.
A study was conducted from June 1999 to May 2000 on behalf of FMCSA, in which a mobile IR camera-based inspection system (IRISystem) was evaluated in four states (FMCSA 2000). The IRISystem enables the operator to recognize wheels, tires, and other components that are markedly hotter or colder than normal, which can signify brake defects and other potential safety problems.
In the FMCSA study, 392 commercial motor vehicles were identified by the operator of the IRISystem and were pulled out of the traffic stream. These vehicles were subjected to a Commercial Vehicle Safety Alliance (CVSA) Level 1 inspection. Most of the vehicles selected for inspection had potential defects or problems as observed by the system operator. Some "control group" vehicles with no evident problems observed in the IRISystem screening were also pulled for Level 1 inspection, to reduce the potential for bias on the part of the Level 1 inspector.
Results from the vehicles selected for inspection using the IRISystem in this field study were compared with inspection results as recorded in the SafetyNet system for all inspections from 1997 to 1999 in the four participating states: Georgia, Kentucky, North Carolina, and Tennessee. The percentage of vehicles placed out of service (OOS) after IRISystem screening (59%) was significantly greater than the percentage of vehicles placed OOS using the previous screening methods (27%), or more than twice as effective. Of those vehicles placed OOS after IRISystem screening, nearly 80% were placed OOS for brake violations.
The percentage of vehicles with brake violations increased by 2.5 times, from 34% with current screening methods to 84% with IRISystem screening (FMCSA 2000, pg. ix).
It was noted that the brake violations reported in this study were not necessarily all OOS violations. That is, a vehicle could have a brake defect recognized as a violation in a CVSA Level 1 inspection, but the defect is not sufficient cause to place the vehicle OOS.
Other relevant findings from this study were:
- The majority (90%) of the problematic wheels reported by the IRISystem operator were cold brakes (pg. 20).
- The majority of problems identified during IRISystem screening were located on the trailer wheels on the far side of the CMV with respect to the IRISystem van. This may have been due in part to wheel covers on the near-side wheels, which obstructed the view of the brake components on those wheels, and the better lines of sight from the IRISystem to the far-side back wheels (pg. viii).
- The presence of brake defects or deficiencies was a good indicator that other repairs were needed on the CMV (pg. viii).
- Mainline screening of CMVs at speeds greater than 55 mph was attempted with the IRISystem, but it was determined not to be practical in this study (pg. 20).
Reference
USDOT. (2000). Evaluation of Infrared Brake Screening Technology: Final Report. Report prepared for Federal Motor Carrier Safety Administration, U.S. Department of Transportation, Contract No. DTFH61-96-C-0007. Report No. DOT-MC-01-007, NTIS PB2001-100010, EDL # 13339, available at: http://www.itsdocs.fhwa.dot.gov//JPODOCS/REPTS_TE//13339.pdf.