Analyzing the use of portable advanced traveler information systems

Abstract

Advanced Traveler Information Systems (ATIS) have been employed over the past two decades to provide travelers with real-time traffic information; one example estimated downstream travel times. Portable ATIS, in the context of this study, can provide real-time traffic information-including advanced travel times, delay times, and reduced average speeds-to motorists by updating portable changeable message signs in rural settings. Currently, there are limited numbers of demonstrations of the capabilities of portable ATIS. This paper summarizes the results of a portable ATIS demonstration project in Redding, California. For the demonstration, four different portable ATISs were deployed on a construction project for a two-week period. These systems included Blufax, iCone, License Plate Reader (LPR) and Adaptir. Three aspects were tested: accuracy, reliability, and usability. Accuracy was evaluated by comparing measured travel times and speeds with a stopwatch measured baseline. Reliability was assessed by monitoring and summarizing the maintenance needs during the demonstration. System usability was addressed in terms of ease of setup and calibration. Overall, the systems accurately estimated travel times within 10 seconds 98 percent of the time for the LPR system and 100 percent of the time for the Blufax, and speeds were within 10 mph 99 percent of the time for the iCone and Adaptir systems. Each of the systems had their own unique challenges with reliability and usability. The results of this study show the promise of using portable systems to measure and display real-time travel times and highlight the challenges that need to be addressed for successful implementation. The study plan for follow up studies summarize the implementation of a future research study that will focus on remedying the downfalls found from the original demonstration project as well as focus on a human factors related experiment measuring vehicle headways with different changeable message sign sequences. These study plans were not implemented but are provided to guide future research work.