The first phase of the San Antonio TransGuide System became operational on July 26, 1995 and included 26 miles of downtown freeway. This paper documents the impact of the system on crashes and incident response times during the first five months of operation and reports the findings of a survey investigation into driver response to the TransGuide system.

The first phase of the TransGuide system includes dynamic message signs, lane control signs, loop detectors, video surveillance cameras, and a communication network covering the 26 instrumented miles. Comparing crash statistics for August – December of 1992, 1993, and 1994, with the statistics for August – December 1995, the paper reports that the system reduced primary accidents by 35 percent, reduced secondary accidents by 30 percent, reduced inclement weather accidents by 40 percent, and reduced overall accidents by 41 percent.

Review of video surveillance data collected throughout 1995 indicated an average reduction in response time of 20 percent. This result compared responses to incidents recorded in the months prior to implementation to those recorded once the TransGuide system became operational. This reduction in response time was input into the CORFLO freeway simulation model. The results showed an average delay savings of 700 vehicle-hours, and a fuel consumption decrease of 2600 gallons per major incident. Using the accident frequency for freeways, these figures translated into an annual savings of $1.65 million.

Survey results reported in the paper indicate improvements in driver confidence with the traveler information available to them after the implementation of TransGuide. Periodic surveys taken after implementation indicated that driver response to posted instructions improved from 33 percent just after implementation to 80 percent at the time of the report.