A study on dynamic bicycle detection and warning device

Abstract

This research pertains to the effectiveness and reliability of a Dynamic Bicycle Detection and Warning sign. In rural areas there are fewer safety options due to financing and environmental design restrictions. Rural roads normally have higher speeds and reduced lane widths with limited or no shoulders. Thus, safety on roads in rural environments should be of great concern for designers. Data concerning interactions between bicycles and vehicles was collected to determine the effectiveness and reliability of the system. Before- and after-installation data was collected via radar traffic recorders and video cameras at two sites along Rim Rock Drive. The data collected before-installation was used to determine a baseline for the interactions between drivers and bicyclists. Two indicators of drivers' reaction were used: vehicle speed and lateral placement in the lane. Three other variables were tested for their effect on the two aforementioned variables: time to opposing vehicle arrival, time between a bicycle and a vehicle, and vehicle class. The variable, lights flashing was added to determine the effects of the system on speed and lateral placement. Results suggest vehicle speed and lateral placement are both affected by the presence of bicyclists. Before-installation affects were primarily seen when the vehicle was observed within 10 seconds or less of a bicycle, or within approximately 400 feet. After-installation the affects were seen up to four minutes after the bicycle passed the site. Driver reactions were similar before and after up to 20 seconds. After 20 seconds drivers moved over more and after 30 seconds drivers slowed down more after-installation. The system detected a bicycle 86% of the time and detected something else 11% of the time. In conclusion the system reduced speeds and encouraged drivers to move over. However, no change in driver behavior occurred under 20 seconds. Speeds averaged around 26 miles per hour which is over the posted speed limit. Most drivers were still utilized the right third of the lane. Therefore, the system was reliable and effective, enhancing bicyclist safety, but driver behavior still poses a danger to bicyclists on Rim Rock Drive.