Increase Comprehension of Blue Light Bicycle Detection Systems By Installing Supplemental Signage on the Far-side of the Intersection, as Opposed to the Near-Side.
Oregon DOT Study Observes High Comprehension for Blue Light Detection with Signage and Eliciting a Countdown Timer.
Made Public Date

Assessment of Bicycle Detection Confirmation and Countdown Devices


Oregon DOT tested a blue light confirmation system in 2018-2020 in which a round blue light turns on when it detects a stopped bicycle. An online survey was conducted to determine comprehension rates of blue light feedback systems and countdown timers. The online survey collected a total of 1,048 responses to study the comprehension of the blue light detection confirmation with and without supplemental signage explaining the blue light. Oregon DOT conducted field tests at six intersections in Portland, Oregon. In addition, a bicycle signal countdown timer was installed at one intersection. Quantitative data from a video review and responses from surveys were used to study how the information provided by the confirmation and feedback device affects the overall cycling experience. A total of 2,428 bicyclists were analyzed and 234 intercepted persons were surveyed. 

Static traffic sign reading "Bicycle detected when blue light on" with a blue light embedded in the middle.
Figure: Blue
detection confirmation light embedded in supplemental sign


Lessons Learned

The survey results and field tests of the blue light detection system and countdown timer suggest the following recommendations for practice:

  • Implement supplemental signage for comprehension in the far side location. Implementing the sign on the far-side showed better comprehension compared to an intersection with blue light detection placed on the near-side. A supplemental sign is required for comprehension as few respondents provided correct responses without a supplemental sign in the surveys.
  • Further investigate the effectiveness of different types of supplemental signs in addition to colors, text, size, and shape. This study explored only a limited number of signs.
  • Differentiate between whether a motor vehicle or bicycle is detected to avoid confusion. Field tests conducted in this project at some locations displayed blue light when either a bicycle or motor vehicle was detected.
  • Place countdown timers in areas in which cyclists are generally accustomed to looking at the signal displays.  Determining the location to install a bike countdown timer is important as cyclists are generally accustomed to looking at the signal displays which are typically placed far-side. As these devices are novel for U.S. cyclists, more research and testing may be needed prior to large scale adoption.
  • Be aware of sampling bias that may be present from the survey as the surveyed respondents may not accurately portray an overall census distribution
  • Organize educational and awareness campaigns for the technology. Educating both cyclists and drivers about the bike detection system across the country is recommended for successful adoption as the results of the online survey of respondents outside of Oregon showed poor comprehension rates.