Arlington recently announced the end of one of the only good things to come out of the pandemic: the widespread implementation of automatic pedestrian phases on many of our traffic signals.
In many areas, pedestrians will have to go back to pushing a button in order to trigger an opportunity to safely cross the street. The response from many has been “pushing a button is not a big deal,” and indeed, pushing a button is not hard or onerous; what is a big deal is the guaranteed additional pedestrian delay that comes along with it, the negative effect on accessibility and the message that it sends.
Unnecessary Pedestrian Delay. How much? It’s complicated.
When the signal is set to go to walk automatically (called “pedestrian recall”), a pedestrian has a decent chance of arriving at the intersection and encountering a fortuitous set of circumstances: the walk signal has already come on and that there is enough time left in the countdown for them to safely cross the street. In this instance, the pedestrian encounters zero delays, they can immediately cross the street.
A pedestrian approaching this same intersection in “actuated mode” where a button press is required, at the exact same point in the signal timing will encounter one of a couple of different circumstances. If a car going the same direction has been sitting there waiting and has tripped the light then they might have a walk signal and still encounter zero delay — or the car may have a green but the signal may not present a walk signal so that it can provide a shorter green for this cross street than the amount of time it takes a person to safely cross, in which case they will encounter a “don’t walk.” Pressing the button now will require waiting the full length of the remaining signal plus the entirety of the green for the crossing direction. If there isn’t a car going the same direction as them to trip the light, then they definitely don’t have a walk signal. Pressing the button will require an unknown wait time that depends on whether that signal is “coordinated” with other nearby signals as well as what the “minimum green time” is for the crossing traffic direction.
With all of the various ways that a traffic signal can be programmed it’s impossible to say at a high level how much these changes are going to slow down pedestrians, but Arlington’s DOT absolutely could. Average pedestrian delay given a set of signal timings is an easy calculation. At a minimum, Arlington should do this calculation for all signals that are proposed to be put back on actuation so Arlingtonians can fully understand what is being proposed.
Safety & Accessibility
While delaying people walking is obnoxious, especially given that it affects us all — we all, at some point in time have to try and cross the street. There is also a safety impact — both studies and a basic understanding of human nature tell us that the longer people have to wait to safely cross the street, the more likely they are to unsafely cross the street. This decision is in clear opposition to our Vision Zero goals.
The press release announcing these changes indicates that they are doing so to “improve walkway safety;” Arlington County spokesperson Jessica Baxter explained to Greater Great Washington that “the theory amongst professionals is when there is manual input by a pedestrian at a walkway, pedestrians are more likely to pay attention to their surroundings.” In all of my time looking at transportation research and learning about transportation safety, I have never before heard this theory.
It is, however, a theory — not peer-reviewed research. It is also predicated on a notion that “distracted walking” is a significant contributor to crashes. This is a trope that has been debunked by actual research — distracted walking has a minimal effect on pedestrian behavior. A meta-analysis of all studies on distracted walking does not show any increased risk for pedestrians. What does increase risk of pedestrian crashes? Speeding, intoxication and driver inattention.
Pedestrian recall is also much more accessible for wheelchair users who may have difficulty accessing the push button and those with low or limited vision who have difficulty locating the push button.
“Corridors where pedestrian activities are less frequent”
Arlington’s press release says that these changes are occurring in “corridors where pedestrian activities are less frequent.” This would make some sense — in areas where traffic is heavy but pedestrians are rarely found, like along Arlington Boulevard, this might make some sense.
The map of intersections to be returned to actuation doesn’t highlight corridors like Arlington Boulevard, however. Why? Because those signals were never fully put onto pedestrian recall in the first place. The corridors where pedestrians are being punished are instead corridors that feature both high traffic volumes and fairly consistent pedestrian traffic like Columbia Pike, Langston Blvd, Shirlington and along Glebe Road in Ballston.
If these areas truly featured extremely low pedestrian activity, then pedestrian actuation would make sense, but so would putting these signals on what is called “hot response” where when a pedestrian pushes the button, the signal changes very quickly — as soon as the walk signal the other direction can be safely counted down to zero. If pedestrian activity is really that low, then the occasional pedestrian “disrupting traffic” by quickly forcing an uncoordinated red light wouldn’t be that disruptive. I’ve only encountered one traffic signal in the region that was clearly set to respond that quickly and it wasn’t in Arlington.
Why now?
This is an especially bad time to make a change that punishes walking. With school going back, but many parents concerned about crowding on buses, parents are making new decisions about how best to get their kids to school. With some adults returning to the office, but on a new or less regular schedule, many people are also rethinking their commutes.
These times of change, when people are actively rethinking their travel patterns, are critical opportunities to get people to try more safe and sustainable ways to get around. We are creatures of habit and we generally get around the way we’ve gotten around before, barring some jarring event causing us to rethink.
A family that decides now that they don’t need that 2nd car is likely to remain car-light for many years. A family that decides that they now do need a second car that they didn’t before, is likely to use that fixed asset and sunk costs to make many more trips by car than they did before.
How should this work?
There isn’t a one-size-fits-all solution here. It’s not as simple as recall = good, actuation = bad, but it’s pretty clear that actuation in many of the areas highlighted is not the right choice given their walkable nature. Unfortunately, these decisions are getting made without community input. Not only is this particular change being made without any sort of public process and without any data to justify it, this is how all signal operation decisions are made.
Arlington’s Master Transportation Plan, which guides our street layout and design, mentions traffic signals only once — and that is to recommend that all county signals be converted to use LEDs rather than traditional bulbs. There is no community-developed, board-adopted guidance on how we operate and time our traffic signals, let alone other operational decisions about our streets. As a result, these decisions are made with no visibility, often by traffic signal engineers who live in car-dependent suburbs relying on their personal judgment, values and experiences which don’t always align with the experience in Arlington’s Urban villages.
Arlington County’s Transportation Commission highlighted these problems back in 2015. A letter to the County Board recommended that the County instigate a public process to develop a signals policy and, acknowledging that this was likely to take several years to get off the ground, recommended several interim, commonsense policies, including “Signals should be adjusted so that pedestrians never have to push a button in order to cross safely and legally throughout the Metro Corridors and in other areas of high pedestrian activity, such as Shirlington and the Columbia Pike corridor.”
I have heard rumors that Arlington may have crafted “administrative guidance” on signal timing and operations, but the Transportation Commission’s request in 2019 to review any such guidance or policy went unanswered, and no other public distribution or review of this guidance has been seen.
What might such a policy look like? Cambridge, MA is a city similar in many ways to Arlington and their Traffic Control Signal Policy sets sensible policies around the average delay experienced by pedestrians waiting for any walk signal (less than 40 seconds), phasing out pedestrian buttons “wherever possible”, implementing “Leading Pedestrian Intervals” (at least three seconds at all crosswalks, with some intersections having an LPI of up to five seconds).
DC’s Design and Engineering manual sets a clear policy on actuation “Pedestrian actuation (requiring pedestrians to push a button) should be used only at actuated signals, and only when pedestrians are present at less than half of the signal cycles at the peak hour.”
So what?
Let’s review – this change:
- Slows down pedestrians
- Decreases safety
- Is being applied to high-pedestrian areas
- Is being applied arbitrarily and without a public process
So what can you do? Speak up – write to the County Manager or the County Board, tag Arlington on social media, or sign on to the Sustainable Mobility for Arlington County petition.
Traffic signal timing & operation is weird, wonky, opaque and largely taken for granted, but it has a real effect on our streets and it sends a message about our priorities. Slowing down walkers, making them beg to cross the street & privileging traffic flow over their safety sends a clear message of Arlington’s priority: that walkers are NOT the priority. We need to send a better message.