Modern Mobility: Beg Buttons – It’s Not About Pushing The Button


Modern Mobility is a bi-weekly opinion column. The opinions expressed are those of the author alone.

Arlington recently announced the end of one of the only good things to come out of the pandemic: the generalization of the installation of automatic pedestrian phases on many of our traffic lights.

In many areas, pedestrians will have to start pushing a button again in order to trigger an opportunity to safely cross the street. The response from many has been “pushing a button isn’t a big deal,” and indeed pushing a button is neither difficult nor expensive; what is important is the guaranteed additional pedestrian delay that accompanies it, the negative effect on accessibility and the message it sends.

Unnecessary pedestrian delay. How much? It is complicated.

When the signal is set to go for a walk automatically (called a “pedestrian reminder”), a pedestrian has a good chance of arriving at the intersection and encountering a fortuitous event: the walking signal has already come on and he there is enough time left in the countdown for them to cross the street safely. In this case, the pedestrian does not encounter any delay, he can immediately cross the street.

A pedestrian approaching this same intersection in “power mode” where a button press is required, at exactly the same time in signal timing, will encounter one of two different circumstances. If a car going in the same direction is waiting and triggered the light, it may have a run signal and still experience zero delay – or the car may have a green but the signal may not have a run signal so that it may provide a shorter green for that cross street than the time it takes for a person to cross safely, 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 entire green for the cross direction. If there isn’t a car going in the same direction as them to trigger the light, then they certainly don’t have a start signal. Pressing the button will require an unknown wait time which depends on whether this signal is “co-ordinated” with other nearby signals as well as “minimum green time” for the direction of the crossing traffic.

With all the different ways a traffic light can be programmed, it’s impossible to say at a high level just how much these changes will slow pedestrians, but Arlington DOT absolutely could. The average pedestrian delay given a set of signal timings is an easy calculation. At a minimum, Arlington should do this math for any signals it is proposed to put back into action so the Arlingtoners can fully understand what is on offer.

Safety and accessibility

While delaying people to walk is abhorrent, especially since it affects us all – we all have to, at some point, try to cross the street. There is also an impact on safety – studies and a basic understanding of human nature tell us that the longer people have to wait to cross the street safely, the more likely they are to cross the street in an unsafe manner. This decision clearly goes against our Vision Zero goals.

The press release announcing the changes says they do it to “improve gateways security; Jessica Baxter, Arlington County spokesperson explained to Grand Grand Washington that “the theory among professionals is that when there is manual entry by a pedestrian on a walkway, pedestrians are more likely to pay attention to their surroundings.” In all of my time researching transportation and learning about transportation safety, I’ve never heard this theory before.

This is however a theory, not peer reviewed research. It is also based on the idea that “distracted walking” contributes significantly to accidents. It’s a trope that has been debunked by real research – distraction from walking has minimal effect on pedestrian behavior. A meta-analysis of all studies on distracted walking does not show an increased risk for pedestrians. What increases the risk of pedestrian accidents? Speeding, intoxication and inattention of the driver.

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”

The Arlington press release says these changes are occurring in “hallways where pedestrian activity is less frequent.” That would make sense – in areas where traffic is heavy but pedestrians are rarely found, such as along Arlington Boulevard, it might make sense.

The back-to-action intersection map, however, does not highlight corridors like Arlington Boulevard. Why? Because these signals were never fully put on pedestrian recall in the first place. Rather, corridors where pedestrians are punished are corridors that feature both high traffic volumes and fairly constant foot traffic like Columbia Pike, Langston Blvd, Shirlington and along Glebe Road in Ballston.

If these areas really had extremely low pedestrian activity then pedestrian actuation would make sense, but it would also make sense to place these signals on what is known as ‘hot response’ where when a pedestrian presses the button, the signal changes very quickly – as soon as walking signal that 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 would not be so disruptive. I only encountered one traffic light in the area that was clearly configured to respond so quickly and it was not in Arlington.

Why now?

It’s a particularly bad time to make a change that punishes walking. With the start of the school year, but many parents concerned about overcrowding on buses, parents are making new decisions about how best to get their children to school. With some adults returning to the office, but on a new or less regular schedule, many people are also rethinking their commute to work.

These times of change, when people are actively rethinking their travel habits, are critical opportunities to get people to try safer and more sustainable ways of getting around. We are creatures of habit and we usually move around as we did before, unless some jarring event forces us to rethink.

A family that now decides they don’t need that 2nd car is likely to stay light for many years. A family that decides they now need a second car that they did not previously have will likely use that downtime and sunk costs to make a lot more car trips than before.

How should it work?

There is no one-size-fits-all solution here. It is not as simple as recall = good, actuation = bad, but it is quite clear that actuation in many areas highlighted is not the right choice given their walkable nature. Unfortunately, these decisions are made without the participation of the community. Not only is this particular change made without any sort of public process and without any data to justify it, this is how all signal exploitation decisions are made.

from Arlington Transport master plan, which guides our layout and design of the streets, only mentions traffic lights once – and that’s to recommend that all county signals be converted to use LEDs rather than traditional bulbs. There are no guidelines developed by the community and adopted by the council on how we operate and time our traffic lights, let alone other operational decisions regarding our streets. As a result, these decisions are made blindly, often by traffic light engineers who live in car-dependent suburbs based on their personal judgment, values ​​and experiences which do not always match the experience of drivers. urban villages of Arlington.

Arlington County Transportation Commission highlighted these issues in 2015. A letter to the departmental council recommended that the county initiate a public process to develop a signage policy and, recognizing that it would likely take several years to get started, recommended several tentative and sensible policies, including “signs should be adjusted so that pedestrians don’t never have to push a button in order to cross safely and legally in subway lanes and other areas with high pedestrian activity, such as Shirlington and the Columbia Pike Corridor.

I’ve heard rumors that Arlington may have developed ‘administrative guidance’ on signal timing and operations, but the Transportation Commission request in 2019 to review such guidance or policy went unanswered, and no other distribution or public review of this guidance has been seen.

What could such a policy look like? Cambridge, MA is a city similar in many ways to Arlington and its traffic control signage policy sets out reasonable policies regarding the average delay experienced by pedestrians waiting for a walking signal (less than 40 seconds), phasing out pedestrian buttons “where possible”, implementing “lead pedestrian intervals” (at least three seconds at all crosswalks, with some intersections having an LPI of up to five seconds).

DC Design and Engineering Manual sets a clear policy on actuation “Pedestrian actuation (requiring pedestrians to press a button) should only be used with activated signals, and only when pedestrians are present within half of the signal cycles at rush hour. “

So what?

Let’s review – this change:

  1. Slows down pedestrians
  2. Decrease security
  3. Is applied to areas with heavy foot traffic
  4. Is applied arbitrarily and without public process

So what can you do? Talk – write to the county manager or county council, tag Arlington on social media or sign the sustainable mobility petition for Arlington County.

The timing and operation of traffic lights is weird, wobbly, opaque and largely taken for granted, but they have a real effect on our streets and send a message about our priorities. Slowing walkers down, making them pray to cross the street and prioritizing smooth traffic over their safety sends a clear message of Arlington’s priority: that walkers are NOT the priority. We need to send a better message.

Chris Slatt is the current chairman of the Arlington County Transportation Commission, founder of sustainable mobility for Arlington County and past chairman of a civic association. He is a software developer, co-owner of Perfect Pointe Dance Studio and a father of two.

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