From Google Streetview.

Why Are Intersections So Dangerous?

A Close Reading of One Pittsburgh Intersection

At the intersection where Liberty and Atlantic Avenues meet Baum Boulevard, there is an apartment building on one corner, two hotels across the apartments in each direction and a park opposite them. At this intersection, cars stop at red lights and go at green ones. People cross the streets at five separate crosswalks. These crosswalks have a walk sign that tells pedestrians when to cross and when to wait. When it’s the pedestrians’ turn to cross, the walk sign shows a symbol of a person walking, which then turns into an orange-red hand that means stop. The hand blinks to count down the remaining time to cross the street. Pedestrians who have begun crossing the street finish, while others who have not yet begun crossing remain on the sidewalk until the walk sign is on again. During this time, cars yield to the pedestrians. Everyone remains safe. There is no confusion, and there are no accidents.

Wouldn’t it be nice if that were the case? Yes, when the walk sign is on, pedestrians cross. But what really happens after that? At the intersection of Liberty, Atlantic, and Baum, cars turn in front of pedestrians when they think they can make it. They feel justified in cutting off pedestrians when the walk sign begins counting down. They continue turning left when the turn light is no longer on in some effort to make the light, even when the pedestrian walk sign has started. I don’t drive in this city, so I can’t contribute the perspective of the cars as they navigate this intersection. I can’t say whether this intersection is made more dangerous due to lack of visibility. I can only guess based on the angular, non-perpendicular nature of the intersecting roads that it may be difficult for some drivers to see pedestrians as they cross. Regardless, pedestrians have to be extra vigilant and can’t take the signals they see for granted. Taking a close look at this particular intersection, especially its signals, can show some of what makes transportation and walkability in cities such a tricky and slippery problem.

This intersection, where Liberty and Atlantic Avenues meet Baum Boulevard, is actually one of the better signaled intersections in Pittsburgh. Not only are there walk signs that count down the seconds left to cross, but there are also accessible pedestrian signals. A voice (intending to help vision-impaired pedestrians) tells people to wait as they press the button to cross and then informs them when the walk sign is on. This intersection needs at least this much signage. Given the many intersecting roads at this often busy intersection and the lack of visibility for both pedestrians and drivers alike, it’s dangerous even with the voices and the beeping and the blinking. Living near this intersection for about a year now, I have had too many close calls to count and witnessed even numerous more. They have ranged from moderately annoying to potentially deadly. Until living in this area, I’d never felt quite so lucky to have grown up with worrisome parents who constantly emphasized “looking both ways” to the point of utter irritation. To my chagrin, this unbreakable habit very well may have kept me alive. It sounds extreme to say, of course, but when I am crossing this intersection, I have to be cautious. It’s not enough to simply follow the signals as they change.

Is it possible that these signals may actually be further complicating the safety of this intersection? Does the thorough nature of the signals make pedestrians less attentive or alert to the traffic on the road? This intersection is designed to work like a mechanical system of moving parts. It is designed for a best-case situation, a scenario in which everyone is focused and moving when told. However, there are human factors at play here. People are people. They are unable to make snap-decisions based on just logic. They have to trust their instincts. They have to trust their bodies. And often, because they are based on survival, our instincts can be selfish. Is it possible that our more selfish instincts devalue the logic and order of computerized signals? If that’s the case, then what would an intersection designed to circumvent instinct look like?

No lights, no signs, no accidents — future intersections for driverless cars

Why is it that we have to make decisions at all when walking and driving? If we think forward to the future, all vehicles will likely be autonomous. Won’t that make us safer, you think? It should make taking a ride in a vehicle safer, in theory, but have you ever seen a simulation of what roads might look like in a world where all vehicles are autonomous? If so, you’d know what a nightmare they look like for pedestrians: at least ten lanes on each road and a massive area at the intersection in which cars with powerful computers can somehow find the right point at which to cross or turn without hitting other cars. These sorts of streets would require massive investments in the infrastructure of the roads themselves, not to mention the extra infrastructure (bridges, tunnels, etc.) that would be necessary for pedestrians. In this sort of solution, it might be safer for pedestrians, but they would likely remain a second-order priority.

In fact, there is something in the very language we use to discuss intersections that shows how we prioritize cars over humans. An intersection is the junction of two or more roads, and a crosswalk is the place where a pedestrian is allowed to cross the road. The road is the land of the cars. Pedestrians are merely tolerated visitors. What if intersections were designed in opposition to that? An intersection where cars have to cross the pedestrian walkway…what would that look like? Might it be safer? Might it at least force drivers to do more than yield to pedestrians? Might drivers be more conscious about pedestrians and “look both ways” before crossing?

Any redesign of an intersection to prioritize the pedestrians would require a change in the way we drive. People are hard to change. Just take a look at the roundabout for an example of how difficult it is for people to understand new traffic patterns. People may be hard to change, but computers just have to be reprogrammed. Transportation is changing, and no matter what, these changes will require huge investments in infrastructure to be realized. As designers, engineers, policy makers, and more all go forward in working out this future, the way they prioritize the human elements in the equation, which are quickly disappearing, will be the real question. Even as cars and buses become autonomous, the pedestrian will still be part of the system, the last human factor for which we’ll have to account.