Signal Timing Recommendations

Signal Timing Recommendations


11 ways to make Boston’s traffic signals work better for people walking

  1. Add concurrent signals at most locations. Concurrent signalization means that people walking receive a WALK signal in the same direction people driving have a green light (i.e., everyone can continue along Mass Ave). This should always be paired with the next item —
  2. Add a Leading Pedestrian Interval (LPI) at signals to give people walking a 5-7 second WALK signal so that they can start into the crosswalk before people driving get a green light. 
  3. Automatic recall of WALK signals should be provided (this means that a WALK signal appears as part of each signal cycle without a push button) at all but rare, mid-block locations. Eliminate all non-functional and irrelevant push buttons. If middle of the night conditions warrant the elimination of WALK signals, change to flashing red signals.
  4. Short signal cycles should be the standard to make walking convenient, reduce delay and encourage compliance by walkers and drivers.
  5. High degree of consistency in signal operations should be used among as many locations as possible so that people walking and driving know what to expect. Perhaps there should be signage noting non-standard timing (e.g. “Wait for All Way Pedestrian Scramble” or “Heavy Turning Volume, Do Not Walk on Don’t WALK”)
  6. Addition of accessible audible signals with activation button should be provided at all signals.
  7. Countdown of full signal should be provided so that pedestrians know how much time remains before opposing traffic will get a green light. Flashing Don’t WALK and then solid Don’t WALK  should be based on appropriate clearance times.
  8. No “leading left” green arrows should be used. This sets up a dangerous situation for people walking who cannot see the leading left and think that crossing is safe, also people driving who turn on a leading left often block the crosswalks for pedestrians. If a protected left turn is required, have it at end of the green.
  9. Set signal phasing with recognition of pedestrian volumes, not just vehicle volumes (e.g. Park/Tremont, Dewey Square, Walk to the Sea). If technically feasible phasing should correspond with time of day and day of week (for example, mid-day Saturday Walk to the Sea, dozens of pedestrians must wait for a very long time while only a small number of vehicles pass by, leading to much crossing against the signal).
  10. Use stop signs to replace traffic signals in areas with light vehicle traffic and short crossing distances (e.g. Milk/Devonshire, Washington/Milk).
  11. After changing the timing for signals, post temporary signage near it: “We recently adjusted the signal timing at this intersection. Did we get it right? Let us know! Use BOS:311”
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