Change Stop Light/Walk Light Setup on Shared Use Trails

[consularrider]

This is something I’ve been thinking about over the past couple of years as I ride the trails in this area. It is time that Arlington County changed the walk lights along these trails to conicide automatically with associated traffic lights rather than requiring a trail user to press a button. There are several stop lights on the W&OD and 4 Mile Run (4MR) Trails in Arlington where the walk light must be triggered by pressing a button. At the intersections at S Shirlington Rd, S Walter Reed Dr, and Lee Highway, this makes no sense. I believe the lights for S 4 Mile Run Dr (first two) and Washington Blvd (third) at these locations are timed and pushing the walk button does not appear to make the light longer. The walk light should be automatic at these intersections.

At the W&OD/Columbia Pike and the 4MR/S Walter Reed Dr intersections there is no traffic light for trail users heading east, only the walk lights since these are T road junctions. Also, both are triggered by approaching traffic, thus if you are arriving at the intersection from the west you cannot tell if the oncoming traffic has a green or yellow light. At the W&OD/S George Mason Dr intersection, again the light is triggered by traffic, but at least the trail user can see the traffic light as well as the walk light. Since these are triggered lights, I suppose the the button must remain so the trail user can trigger the light when there is no road traffic, but again, if there is road traffic, it should also trigger the walk light.

[Tim Kelley]

I passed your comments along to our engineering team and this is the explanation I received:

“The reason the pedestrian pushbutton is required at these intersections is that if no pedestrian phase is required, the traffic signal will default to providing the shortest necessary green time for the vehicles on the minor street in order to minimize the major street delay. This default minor street green time may not be enough time for pedestrians to safely cross the street, thus the green pedestrian signal is only displayed if a pedestrian phase is called. At the intersections mentioned, the trail crossing follows the minor street (Four Mile Run Dr. at Shirlington Rd., Four Mile Run Dr. at Columbia Pike, etc.) therefore the pushbutton is required to provide the additional green time for pedestrians to cross.

This type of signal control (requiring the pedestrian phase to be activated) is consistent throughout most of Arlington outside of the Rosslyn-Ballston corridor. Pedestrians, and cyclists who are crossing as pedestrians, should only cross when a green pedestrian signal is displayed regardless of what is shown on the overhead traffic signal.”

[Author]

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