RESEARCH - Enforcement of Cycle Passing Distances
Cycling advocates in BC would like to see our government enact a safe passing distance law so that drivers are aware of how much space they must leave between their vehicle and the cycle as they drive by. Two US cities, Grand Rapids, Michigan and Knowville, Kentucky have such laws and were chosen by NHTSA for a study of how high visibility enforcement of the law influenced passing distances.
Here is the document's abstract:
This study selected Grand Rapids, Michigan, and Knoxville, Tennessee, to implement high-visibility enforcement (HVE) programs to increase compliance with laws requiring drivers to leave a minimum distance when passing bicycles.
In Grand Rapids, a local ordinance required leaving 5 feet, and in Knoxville, the State law and local ordinance required a minimum 3 feet to pass. Police in both cities used the same type of ultrasonic measuring device to determine if drivers passing decoy officers on bicycles were too close.
The ultrasonic measuring device was modified to store data and was used to collect evaluation measures by two groups of data collection riders— “staged riders” who rode repeatedly on routes on which enforcement was focused, and “volunteer riders” who used their bicycles as primary transportation.
Each city developed its own publicity program to increase the visibility of the enforcement. HVE programs continued for approximately 4 months in each city.
Results showed that the average passing distance in both cities during baseline was already well in excess of the prevailing legal requirement, but violations (passes closer than 5 feet in Grand Rapids and closer than 3 feet in Knoxville) were still high (26.0% in Grand Rapids and 5.0% in Knoxville). By the end of the HVE programs, statistically significant increases in average passing distance and significant decreases in violations were achieved in both cities.
Police had no problems using the ultrasonic measuring device to identify violators and chose to issue more warnings than tickets.