Source: bluebikelane (PDF)
Many European cities use colored markings at bicycle–motor vehicle crossings to reduce conflicts. To determine whether such colored markings help improve safety at American bicycle–motor vehicle crossings, the city of Portland, Oregon, studied the use of blue pavement markings and a novel signage system to delineate selected conflict areas. The University of North Carolina Highway Safety Research Center (HSRC), under contract to FHWA, analyzed the project data. From 1997 to 1999, Portland marked 10 conflict areas with paint, blue thermoplastic, and an accompanying “Yield to Cyclist” sign. All of the sites had a high level of cyclist and motorist interaction, as well as a history of complaints. The crossings were all at locations where the cyclist travels straight and the motorist crosses the bicycle lane in order to exit a roadway (such as an off-ramp situation), enter a right-turn lane, or merge onto a street from a ramp. The study used videotape analysis and found most behavior changes to be positive. Significantly higher numbers of motorists yielded to cyclists and slowed or stopped before entering the blue pavement areas, and more cyclists followed the colored bike-lane path. However, the blue pavement also resulted in fewer cyclists turning their heads to scan for traffic or using hand signals, perhaps signifying an increased comfort level. The overwhelming majority of cyclists and close to a majority of motorists surveyed felt the blue areas enhanced safety. Colored pavement and signage should continue to be used and evaluated in bicycle–motor vehicle conflict areas.