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Sunday, September 22, 2019

Barriers Against What?

There have been dire warnings recently that car manufacturers might try to exert their influence to take over city streets at the expense of pedestrians (again). A recent flare up followed the suggestion that some executives were considering the installation of gates at intersections to keep pedestrians from crossing against the light and interfering with autonomous vehicles. The backlash from urbanists was immediate: We should not repeat the mistakes of the past when cars were first introduced into cities. People should not be penned in on the sidewalks like cattle. Etc.

A couple of examples:

Caution is warranted, of course. The ability of autonomous cars to successfully navigate dense pedestrian areas is dubious, and some of the materials released by the auto industry have been outright frightening (see below). I agree with the need to be vigilant about the policies that may redesign our cities very quickly, setting new patterns that may hold for generations to come. In this case, though, it seems like a knee jerk response of the "if it's good for cars, it must be bad for pedestrians" variety. The idea surfaced, after all, as a solution to the potential problem of pedestrians interfering with the automated vehicles, which might become paralyzed if people deliberately walk in front of them, knowing that safety procedures designed to avoid injuring people will make them stop.

Nonetheless, I am fairly optimistic that automated vehicles can be leveraged to transform the places we live for the better, and I see crossing gates as an acceptable tradeoff. Likely enough, they could become a welcome addition to our streetscape.

Let's start by asking ourselves how much more autonomous vehicles could possibly take over. Motor vehicles already occupy the vast majority of our public right of way. At intersections, the motor vehicles take the majority of the signal time, with only a meager share of the time allowed for pedestrians. Worse, the pedestrian crossing time is often shared with conflicting vehicle movements, so people trying to get across the street must be constantly vigilant for their own protection. Moreover, there is a small handful of drivers who have an outsized impact by intruding on the residual space and time left over for pedestrians in all manners of ways (parking on the sidewalk, failing to yield, losing control and running over people at the bus stop, etc.). Pedestrians are already pushed into pens on the side of the road, and they're not even necessarily safe even when they stay where they're told.

Yet the circulation and parking of today's driver-operated vehicles is highly inefficient in its use of the allocated space. Autonomous vehicles may offer a great deal of potential for reducing the physical footprint as well as the threat of death from cars. Paking lanes can disappear (a process in itself that requires vigilance for equitable outcomes), moving lanes could be narrowed, and greater efficiencies from reduced following distances and better lane-change coordination may allow for a significant reduction in the number of moving lanes as well. That space can all be reallocated for pedestrian and streetscape improvements.

The urge to defend jaywalking is particularly strong in New York. It reflects the realities of a city where masses of pedestrians on crowded sidewalks are able to negotiate large gaps in traffic on relatively narrow streets with predictable signal lights. These conditions are not particularly common outside New York, and these informal coping mechanisms will not be as relevant to a future of autonomous vehicles in New York City, either.

Pedestrians starting to cross the intersection after traffic has cleared, before the light has changed, is mostly what people refer to when they talk about "jaywalking" as something that is appropriate and useful. Nobody is talking about walking out into an the intersection in the middle of a platoon of vehicles that have the green light. This jaywalking works in regular practice because the pedestrians are able to read the traffic and manage the available time between platoons of vehicles better than relying on the fixed signal timing. This is the product of dumb traffic signals.

Photo by Dax
Smart signals communicating with smart cars in the future should not continue to display a Don't Walk hand after the vehicle platoon has cleared the intersection. A gate controlled by a smart signal would not inhibit pedestrians from making full use of the intersection. It could, however, add an additional measure of safety.

As a parent, I generally feel positive toward the idea of a physical barrier. It would help prevent children from accidentally running in front of a car. Intersections are places of constant fear and hyper vigilance for anybody responsible for the safety of a child. My wife's initial reaction was similar:
Me: There has been some discussion about putting gates at intersections that only open for pedestrians when they have the light... 
My wife: Might be good for safety.
Over the years, I have observed my increased comfort with any streetscape that provided more of a barrier between cars and my young son.

Beyond the anxiety of supervising children, I think this is relevant for "distracted walking" as well. I am skeptical of the efforts to demonize pedestrian cell phone use as the cause of more pedestrians getting run over, but I have observed over the past few years that more pedestrians in Manhattan seem to be waiting for the signal light at the corner while using their phones instead of actively looking for opportunities to cross before the light changes. This gradual change in pedestrian behavior would be compatible with gates that enable safe passage for pedestrians who do not want to dedicate their full attention to avoid getting killed by a car.

When I consider the overall transformation that could be possible by leveraging autonomous vehicles, I am hopeful. Such a vision is not guaranteed, or even necessarily likely. It will require buy-in from enough of the public and the industry to congeal in the political chambers as workable policies. It will require a collective effort to redesign our cities into more enjoyable places. And, admittedly, that just won't happen without some periodic dire alarm bells about the threats that could be posed by unfettered access for cars.

The vision I see entails a combination of physical design, operational protocols, and pricing models that prioritize transit, bikes, and scooters for the majority of trips in cities, and flexible shared-ride service for much of the closer hinterlands. The remaining autonomous vehicles will need only a fraction of the space on streets, which can then provide wider sidewalks, substantial space for rain gardens and social activities, shorter crossing distances, and much more time for pedestrians to use the intersections uninterrupted. Having gates that periodically close to allow platoons of autonomous vehicles to pass, like occasionally waiting for a train to go through, seems like a fine way to protect children and people using their mobile devices.

Ultimately, it is a question of what we are erecting barriers against. If they become barricades that inhibit people walking around the city, as many have feared, it would indeed be a tragic mistake. Safety barriers that take more of the risk and stress out of the experience of walking around town could be a wonderful opportunity. If that prevents malicious interference with automated vehicles, that could be helpful too.

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