Improving the Bicycle Detection Pavement Marking Symbols to Increase Comprehension at Traffic Signals

The City of Portland and many other agencies provide pavement markings such as the MUTCD standard 9C-7 bicycle detector marking to help people using bicycles call for a green indication at a signalized intersection. Previous research has shown that approximately half of cyclists do not intuitively understand the marking, and therefore may not be detected by the traffic signal necessitating running the red indication. Building on previous research with the 9C- 7 bicycle detector marking and blue light detector feedback devices, there are two objectives of this research: 1) do users comprehend the 9C-7 marking and the blue light detector feedback device? 2) Does bicyclist behavior change due to a descriptive bicycle detector marking? In this study, 60% of intercept survey respondents correctly identified the existing 9C-7 marking and approximately 72% correctly identified the meaning of the blue light detector feedback device. A survey of cyclists in the field showed a 30% increase of user comprehension when descriptive text was added to the 9C-7 marking. When the more descriptive bicycle detector marking was installed at a recently re-constructed intersection, there was a statistically significant increase of bicyclists waiting on the new bicycle detector stencil. However, there was not enough data to support a statistically significant reduction of red light running cyclists.