Sources say that 45 percent of bicycling accidents involving motor vehicles occur at intersections. Bicyclists are at high risk for injury in any traffic accident with a car or truck. Protective gear, reflectors and proper lighting on a bicycle offer little protection against the mass of moving metal and hazards created in the infrastructure of an intersection–concrete curbs and the pavement of a street can cause injury as a bicyclist falls.
Pleasanton, California is testing a system to reduce the risk of injuries in intersections resulting from potential bicycle accidents. The city is reportedly the first in the nation to test a system of sensors in intersections that detects bicyclists and motor vehicles from up to 300 feet from an intersection.
The system, called the “Intersector,” uses high tech microwave motion sensors to detect cyclists and motorists who may be approaching the intersection. The system attempts to discern whether a bicyclist or motorist is approaching.
When a bike rider alone is detected the Intersector system adjusts the timing of green and red lights one way; when the system detects a bike rider and a motorist approaching the intersection, a different timing pattern for the lights is programmed in an effort to increase safety.
Alameda County ranked number two in Northern California for the number of bicycle accidents that occurred between 2005 and 2009. During that time frame, 3,400 bicyclists were involved in an accident. That is roughly 1,150 more bicycle accidents than those recorded in San Francisco during the same time frame. Obviously, not all of the overall Alameda County bicycle accidents happened in the city of Pleasanton.
Pleasanton began testing the sensors early this year, with one system installed in January. The city expects to have as many as six more intersections added to the test by November.
Sensors in roadways are not a new concept. Many cities have sensors imbedded in the road in order to attempt to detect traffic patterns for the purpose of timing traffic control signals at intersections. However, more traditional systems may have difficulties in detecting bicyclists.
The imbedded sensors may not detect a bicyclist who passes by the sensor, instead of traveling over the sensor. Other difficulties can arise in detecting today’s bicycles because not all are made of metal, which is a requirement in traditional traffic flow sensors.
Source: Governing, “How Intersections Now Sense What Will Zoom By,” Jessica Mulholland, Oct. 4, 2011