#38 – Bicycle Detection Program

Santa Cruz, California

Cheryl Schmitt, Bicycle/Pedestrian Coordinator, Santa Cruz, CA


Bicyclists’ inability to “get a green light” has been the cause of many a call to the Traffic Engineering office. The callers typically display frustration, confusion, and a sense of modal discrimination. The Bicycle Detection Program was developed as a two-phase strategy to address these complaints. Phase 1 involved correcting actual detection problems at each traffic signal. Phase 2 involved educating the public about how and where to be detected at traffic signals.




The City of Santa Cruz has 40 signalized intersections. Thirty intersections use inductive loop detection and 10 intersections use video detection. Typical loop layout is three “A” loops and a stop bar “Q” or “D” loop for each motor lane. Bicycle lanes typically have a bike “Q” loop at the stop bar for the minor legs. Bicycle detection is not always provided for the major legs if the signal rests in green on the major legs. Video detection intersections use Peek Video cameras. Four arterial corridors are interconnected using Traconet with Traconex controllers.


Phase 1: Engineering

  1. Citizen requests and work orders regarding bicycle detection were compiled to determine signals with a history of complaints.
  2. A work list was created prioritizing locations and the stated complaints, with proposed short-term and/or long-term solutions and cost estimates.
  3. The locations were tested by the Bicycle/Pedestrian Coordinator and the Traffic Signal Technician in the field. The Coordinator rode an aluminum frame bicycle over each lane and the Technician recorded the level of detection at the signal cabinet. Detection levels were adjusted and re-tested as necessary to detect the bicycle (short term solution).
  4. Long-term solutions include cutting new loops, adjusting cameras, and installing bike push buttons where necessary. These repairs are funded from an annual Minor Traffic Signal Maintenance budget.


Phase 2: Education

  1. The lead loop in left-turn lanes, curbside lanes without bike lanes, and bike lanes were marked with the Manual of Uniform Traffic Control Devices bike detector marking if sawcut lines were not visible.
  2. A brochure was developed to describe how traffic signals work and to explain where bicyclists should position themselves on sawcut lines in order to be detected. This brochure is available on-line on the City's Web site at http://www.ci.santa-cruz.ca.us/pw/trafeng/bikedet.pdf
  3. Signal detection is discussed at the 2-hour bicycle safety class required of all applicants to the regional bike loan and e-bike rebate programs. Over 500 participants have received the Bicycle Detection brochure through this program.
  4. Bicyclists on the local e-mail bike list were kept abreast of the program and encouraged to contact the Bike/Pedestrian Coordinator with comments.

Evaluation and Results

Complaint calls to the Traffic Engineering office have decreased dramatically. Bicyclists on the local e-mail bike list and bicyclists’ newsletter describe a greater level of confidence in being detected and willingness to wait through the red.

Conclusions and Recommendations

Some of the technical problems are difficult to solve. Turning up the sensitivity on the detector amplifier to detect bikes will sometimes work for a period of time, but it usually ends up “locking on,” causing a maximum recall condition. Rapidly decaying street infrastructure is resulting in more loop failures, with no funding in sight for repairs.

Video detection is much more reliable overall, but there was a learning curve for the field crew to become proficient with it. Nevertheless, the Bicycle Detection Program has been and continues to be a success.


Loops are approximately $500 each; for bike detection, there are typically two loops per direction of travel. Video detection is approximately $35,000 for a complete intersection installation. Pedestrian/bicyclist push buttons with the conduit and conductor to the controller cabinet is approximately $1500; each pole with push button is about $300.



Cheryl Schmitt
Bicycle/Pedestrian Coordinator
City of Santa Cruz Public Works Department
809 Center Street, Room 201
Santa Cruz, CA 95060
(831) 420-5187

The modification (bicycle detector markings) that is the subject of this case study is allowed by the Manual on Uniform Traffic Control Devices (MUTCD), but if used, one specific design is required. The specific markings used by Santa Cruz and shown in the article are not in conformance with the technical provisions of the marking shown in Figure 9C-7 of the MUTCD.