The camera-based system has great potential to reduce transit bus side crashes. This study reviewed and compared mirror-based, sensor-based, and camera-based systems for side collision avoidance.It evaluated the effectiveness of camera-based systems to reduce transit bus side crashes through measuring the reduction of blind zones and analyzing the results of controlled driving tests and driver surveys using sideview video systems. The result from measurements of blind zone reduction showed that the camera-based system with a regular angle lens (no distorted image) can reduce about 64 percent of the blind zones of a flat mirror system. It can reduce about 43 percent of blind zones of a common combined flat and convex mirror system. Using a wide-angle lens, the blind zones on the both sides of transit buses can be completely eliminated. The result of the controlled driving test from 28 bus drivers was positive on distance/depth perception and lane change maneuvers using sideview video systems. Most bus drivers were able to adapt to the sideview video system and quickly learn how to use the system to drive without mirrors. While using the video system, the bus drivers could perceive distance similar to the mirrors while the bus was in motion. By using the sideview system, bus drivers could still see the vehicle in the blind zone of mirrors. The driver survey results confirmed that bus drivers participating in the study valued the benefits of sideview video systems, with some reservations about system reliability due to unfamiliarity with the new system. It was recommended that the sideview video system in this study be further enhanced for evaluation through actual deployments to ensure its reliability and effectiveness. Download the final report.

For more information, contact Pei-Sung Lin at, Chanyoung Lee at, Achilleas Kourtellis at, or Meeta Saxena at