Use of "optical speed bars" to reduce accidents - The Calgary experience.

The use of "optical speed bars" on a major freeway exit ramp for the purpose of reducing accidents at the ramp terminus is tested. Observations to date indicate that the speed bars do seem to reduce accidents, but meaningful statistics can only be obtained through several years of data collection and installation of more test sites. Nevertheless, from the data collected to date, it appears these bars have the greatest impact on first time users, are inexpensive to install and have the potential to reduce the severity of accidents.