2 Evaluation Scope and Objectives
2.1 Problem Statement
Weather presents a serious challenge to safety and mobility on our national system of roads and highways. Winter storm events present obvious snow and ice hazards to driving, but even relatively small weather events, such as light rain or occasional fog can dramatically impact traffic flow and safety at any time of year. The FHWA reports that in the presence of adverse road weather conditions, every year on our highways “nearly 7,400 people are killed and over 690,000 people are injured.”1 In addition to the obvious safety implications of adverse weather on roads, weather impacts can be very costly in terms of lost time due to congestion, lost wages and productivity, and the costs to state DOTs seeking to maintain mobility and safety on their road system.
The FHWA seeks to address these weather-induced transportation challenges proactively and in a variety of ways, such as through the provision of better information, advanced warning of weather events, more precise knowledge of the timing, location and extent of likely weather impacts, better integration of weather into traffic operations, and application of advanced tools to support decision making. Solution strategies include development and promotion of new technology and tools as well as institutional and organizational culture changes that encourage awareness building, knowledge transfer, and the adoption and effective use of these tools.
The deployment of an MDSS in Maine offered an opportunity to assess the ability of this tool to support MaineDOT in better addressing the challenges presented by winter weather to their road maintenance activities. The expectation is that an MDSS offers state DOT maintenance personnel a tool that can help them achieve greater benefits and reduced costs; that is, the benefit-to-cost ratio should increase. This evaluation was initially designed as a system impact study to measure the effect of an MDSS on this ratio but the scope was adjusted due in part to the very limited quantitative data related to the effects of an MDSS on MaineDOT's maintenance operations. A case study evaluation more accurately reflected the conditions encountered in Maine and offered a better opportunity to identify findings and benefits associated with an MDSS that will be of broad value to other states. The primary objective of this case study evaluation is to understand the uses and value derived from an MDSS in one location to add to a body of evidence that could support MDSS deployments among other DOTs.
2.2 Scope of Evaluation
This evaluation developed a case study of an MDSS during the winter season of 2006-2007 in and around the Portland, Maine metropolitan region of southern Maine (MaineDOT Region 1). The evaluation was initially designed to collect baseline data before deployment and use of the MDSS followed by post-deployment data collection that would allow an analysis of the differences between the before and after periods as a method to identify changes due to the use of this type of tool. However, it was apparent from the start of the evaluation that the usual conditions for a before-after system impact study design were not in place under the circumstances. The MDSS deployment had occurred prior to the initiation of the evaluation, and no time was provided for the users of this system to adjust and adapt to the new technology. The winter had already begun, and data collection could not be delayed. There was essentially no distinction between baseline and post-deployment periods.
A decision was made part way through the evaluation to modify the approach to conduct a case study to address the following specific goals:
- Identify lessons learned from MaineDOT’s experience using an MDSS.
- Identify effective strategies for deploying an MDSS.
- Identify institutional issues and implementation costs faced by MaineDOT in integrating an MDSS into their winter maintenance decision processes and how these issues were addressed.
- Assess how an MDSS supplements the suite of tools available to MaineDOT for making winter maintenance decisions.
- Assess the operational use of an MDSS by reconstructing each of the winter storm events and Maine DOT’s management of those events.
- Assess the potential benefits that an MDSS could offer MaineDOT if it were utilized more comprehensively.
This approach involved a focus on the institutional processes and experiences of the MaineDOT Scarborough crew as they experimented during this first winter period with an MDSS and sought to find effective ways to use this new tool in support of their maintenance operations. The evaluation methods, that were applied initially and involved a detailed reconstruction of the Scarborough crew’s strategy for responding to each new winter storm event, provided a detailed understanding of these institutional processes. This allowed for a seamless and constructive transition from a system impact study design to a case study design for the evaluation.
1 http://www.rita.dot.gov/cgi-bin/ExitPage/good_bye.cgi?url=http://ops.fhwa.dot.gov/Weather/q1_roadimpact.htm.