Mapping self-driving cars

Crosswalks and self-driving vehicles: Mapping 311 requests in testing locations in Pittsburgh

Uber’s self-driving fleet remains grounded a week after a pedestrian was killed in Arizona.

A marked crosswalk in the South Side

A marked crosswalk in the South Side

MJ Slaby / the incline
MJ Slaby

Uber’s self-driving vehicles remain off the streets — including in Pittsburgh — a week after a crash in Arizona is believed to be the first-known pedestrian fatality involving an autonomous car.

Elaine Herzberg, who was struck while pushing a bike across an eight-lane road and later died, “appeared in the camera right before she was hit,” per The New York TimesSlate reported that the road had one crosswalk in nearly two miles, and she wasn’t in the crosswalk.

Video from inside the autonomous vehicle showed “the safety driver looking down, away from the road. It also appeared that the driver’s hands were not hovering above the steering wheel, which is what drivers are instructed to do so they can quickly retake control of the car,” per the Times.

This is the third time Uber has suspended testing in Pittsburgh, the first location to pick up Uber users in autonomous vehicles starting in September 2016. The other two times Uber paused testing in Pittsburgh were in March 2017 after a crash in Tempe, Ariz., where a car failed to yield to the self-driving car and in September 2017 after a crash near the Hot Metal Bridge. In both cases, there were no serious injuries.

Uber has not said when its self-driving fleet will return to the streets, but other companies like Argo AI have continued testing here during Uber’s hiatus.

Wickerham_Uber_TheIncline_09_20_2017_65
Jared Wickerham / for the incline

Autonomous cars and crosswalks

It’s reasonable to expect that self-driving cars see everything around them, said Philip Koopman, a Carnegie Mellon University robotics safety expert. The technology is processing information from 360 degree cameras multiple times per second, which is faster than a person can process.

“In general, you would fully expect that an autonomous vehicle has better situational awareness than a person,” Koopman said, adding that the self-driving car doesn’t get distracted and doesn’t take its eyes off the road.

But that doesn’t mean it understands the details that a person does.

He said to think of it like this: When a teenager gets in the car to drive for the first time, it’s not fair to say they have no experience. They’ve known for years what a pedestrian looks like and that a ball rolling into the street will likely be chased by a child.

A self-driving car is learning all those things — and how to drive — at once.

Self-driving cars are going to have to learn to adapt to social norms, he said. Pedestrians know what it means when a human driver waves them on. And for now, the autonomous vehicles have a safety driver who can do the same thing and make eye contact.

He said it’s reasonable to expect that self-driving cars should know such context about driving, like how to tell when someone might step into the street.

How good are the cars at that right now?

Koopman said only the companies know, and that’s arguably a problem. “We think they are good, because they say they are.”

Some companies have internal safety testing that they don’t publicize, he said adding there’s nothing stopping the companies from releasing that information.

“They could do it if they wanted to,” Koopman said.

NYT article revealed that Uber’s cars were “not living up to expectations months before” Herzberg was killed in Tempe, Ariz. Per the Times: 

The cars were having trouble driving through construction zones and next to tall vehicles, like big rigs. And Uber’s human drivers had to intervene far more frequently than the drivers of competing autonomous car projects.

Waymo, formerly the self-driving car project of Google, said that in tests on roads in California last year, its cars went an average of nearly 5,600 miles before the driver had to take control from the computer to steer out of trouble. As of March, Uber was struggling to meet its target of 13 miles per “intervention” in Arizona, according to 100 pages of company documents obtained by The New York Times and two people familiar with the company’s operations in the Phoenix area but not permitted to speak publicly about it.

On Wednesday, advocacy group Bike Pittsburgh put out a call to action asking for support for a bill in the U.S. Senate that would require autonomous vehicles to pass a vision test that includes detecting and responding to bicyclists and pedestrians.

A year ago, BikePGH released the results of a survey that found most respondents felt safer cycling and walking next to autonomous vehicles because the cars go the speed limit, don’t block crosswalks at red lights and use turn signals, unlike all human drivers. Some, however, noted that because the cars are so cautious it makes interactions unpredictable, given that “usual aggressive drivers” are the norm.

About 25 percent of Pittsburgh’s traffic fatalities are pedestrians, per the BikePGH crash report.

BikePGH also collected several comments through its Submit Autonomous Vehicle Experience, or SAVE form, that noted self-driving cars that didn’t yield to pedestrians waiting near a crosswalk.

What does all of this mean for how pedestrians should interact with self-driving cars on the street next to them?

“You should treat a self driving car just like any other car,” Koopman said, adding that cars are always a lot bigger than a person, so if a pedestrian is in the crosswalk and the car isn’t slowing down, “I’m not going to press my luck.”

Pittsburgh’s crosswalk requests, mapped

Every intersection is a crosswalk whether it is marked or not, said Amanda Purcell, municipal traffic engineer with the city. So when the city fields requests for new crosswalks, it’s really about adding or even repainting lines, she said.

So what do crosswalk requests look like in Pittsburgh — especially in neighborhoods where self-driving cars are testing?

The Incline pulled 311 data from the Western Pennsylvania Regional Data Center and found that there were 288 requests for new crosswalks from 2015 to now. So far this year, there have been 13 requests for new crosswalks in Pittsburgh through 311.

While the 311 data doesn’t include exact locations, it does show neighborhoods for the requested crosswalk. The data also doesn’t include information on Allegheny County or PennDOT-owned roads. Read more about the data here.

Below is a map of new crosswalk requests by neighborhood. One request didn’t include a location, so it’s not included in the map. (See an interactive version here.)

311 requests for new crosswalks

Now here’s the same map, but just with neighborhoods where self-driving cars were spotted, per The Incline’s self-driving car map. A lightest color was added to this map to indicate neighborhoods where self-driving cars were spotted but there were no crosswalk requests. (See an interactive version here.)

311 requests for crosswalks in neighborhoods with self-driving cars

How Pittsburgh gets new crosswalks

If the the city decides to add crosswalk markings, it’s often to promote the safest crosswalks, Purcell said. Sometimes that means directing pedestrians to a nearby marked crosswalk at a traffic signal.

When 311 receives a request for a new crosswalk, it goes to a field engineer who determines if crosswalk lines should be added, said Katy Sawyer, a city mobility engineer. They consider things like visibility, the volume of vehicle and pedestrian traffic and if the location is close to a traffic signal.

If the engineer decides there should be a crosswalk, then a work order is sent to Purcell. If she approves it, it then goes to the sign shop to make it happen. Purcell estimated that about half of crosswalk requests are approved, and sometimes it’s just repainting lines that were once there.

Most residents will get a response with the outcome of their request in a week or two, Sawyer said, adding that the city doesn’t paint in the winter so there will be a backlog of requests until about May.

Pittsburgh’s Department of Mobility and Infrastructure is currently working on a crosswalk policy that outlines the process and answers questions for residents, she added.

When it comes to self-driving cars, Sawyer said self-driving vehicles need to be able to detect people and not rely on crosswalk lines to know where people are, adding that it would be nearly impossible to mark every crosswalk in the city and probably take five times the staff to do it.