Technical Resources

Bicycle Signal Challenges in the United States

IA-16 establishes the guidelines under which U.S. agencies may use bicycle signal indications at this time. These guidelines limit their use to locations where there is no conflicting traffic or turn movements across the bikeway while the bicycle signals are green. This can be done through control of left-turn and/or right-turns by providing protected movements that display a red signal while the bicycle signals are green. These provisions normally require separate turn lanes. Alternately, bicycle signals can display the bicycle signal green as an exclusive phase, while all other conflicting directions are stopped, but this approach can result in long delays for bicycle users. Washington DC documented their experience with this sort of arrangement in 2012i. For information on this see the following: https://ddot.dc.gov/sites/default/files/dc/sites/ddot/publication/attachments/ddot_bike_evaluation_summary_final_report_part1_0.pdf.

Some agencies have installed applications that do not comply with the requirements stated in IA-16 by utilizing the FHWA Request to Experiment (RTE) procedure outlined in Paragraphs 1 through 11 of Section 1A.10 of the MUTCD. This requires before, during, and after reporting, and permitted improvements are subject to be removed if problems become evident or at the request of FHWA. These RTE cases allow for innovative applications to be tested in the field which leads to better understanding of effective design practices.

An additional challenge is that IA-16 allows for small 4” lens-diameter bicycle signals for near-side mounting on posts. These smaller signals have visibility and installation space advantages.  But they are not readily available from U.S. manufacturers, and European models may not use U.S. voltages.