This paper presents baseline findings from a panel survey of regular peak hour travelers of the US-75 corridor in Dallas, Texas, and the I-15 corridor in San Diego, California. This survey was conducted as part of the evaluation of the Integrated Corridor Management (ICM) Initiative. The baseline survey, conducted before the deployment of the ICM Initiative, collected data on travelers’ typical travel in the corridor, their satisfaction with their peak hour trips, their awareness and use of real-time traffic information, and their satisfaction with the information. In addition, recruited respondents were asked to complete brief pulse surveys administered immediately following incidents in the corridor to measure the use of information and its impact on travel during incident conditions. The surveys provide insights on travelers’ use of real-time traffic and travel information and its impact on their travel decisions in two major metropolitan corridors. Through a comparison of the two sites, the findings illuminate how the use of traveler information is conditioned, at least in part, by regional and situational context. In Dallas, respondents were faced with greater traffic congestion and delay, and they were more likely to consult information for their peak hour trips in the corridor. Their use of radio and electronic message signs, two of the most common sources of information, was significantly higher compared with the San Diego sample. In addition, the availability of alternate routes may affect how travelers use real-time traffic information. In Dallas, where respondents reported greater use of alternate routes, both under typical circumstances as well as in the face of severe congestion, significantly more respondents used real-time information to make routing decisions.

Variable tolling was implemented on the SR-520 Bridge in the Seattle, Washington, region in 2011 as part of a federally funded initiative to reduce traffic congestion. R-520 tolls varied by time of day up to a maximum of $3.50 each way ($5 for nontransponder payments). A nearby parallel facility, Interstate 90, remained a toll-free alternative across Lake Washington. Tolling was accompanied by investments in public transit and traffic management technologies and by efforts to promote telecommuting. A two-stage panel survey approach was used to analyze the impacts of this tolling program on corridor users’ daily travel choices. In each survey wave, more than 3,000 respondents from roughly 2,000 households completed a 2-day travel diary, with additional detail on trips in the Lake Washington corridor, plus a personal survey on general travel behavior and attitudes. Key survey findings included a marked decrease in respondents’ travel in the corridor after tolling, particularly on SR-520, which experienced a 47% reduction in recorded trips, and significant diversion to I-90. Shifts from SR-520 to I-90 were most pronounced among men, those in lower-income households, and those with less workplace schedule flexibility. There were also increases in transit mode share in the corridor, while carpooling and telecommuting levels were relatively stable. In the posttolling survey, respondents registered an overall increase in satisfaction with their commutes and less stress associated with driving. Reported satisfaction with the speed and reliability of individual trips on SR-520 also increased substantially, and personal attitudes shifted slightly in favor of tolling.

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