Researchers at Portland State University found that drivers are not only less likely to stop for black pedestrians at a crosswalk, but they also give them less room to cross.

The research expands on a widely reported 2015 study done at a marked crosswalk near the university's downtown campus, which found drivers are less likely to stop for black men trying to cross the street at a crosswalk than white men.

The second round of testing, conducted at an intersection in Southeast Portland, found that black women have largely the same experience as black men. For both groups, cars are significantly less likely to stop than for white pedestrians.

The first car stopped for 57 percent of white pedestrians, compared with 44 percent of black pedestrians. More drivers also passed black pedestrians on average before one stopped to allow the pedestrian to cross.

What's more, the research found that drivers who did stop for black pedestrians were more likely to "encroach" on the crosswalk by stopping beyond a marked white line.

"That's where we saw some of our strongest results," said researcher Kimberly Kahn of the Transportation Research and Education Center at PSU. "That was very consistent, that for both white men and white women, cars were stopping further back. They were giving the pedestrian more space."

That could contribute to higher fatality rates for minority pedestrians, Kahn said.

During the most recent study, the pedestrians wore identical clothing and repeatedly crossed the same intersection at Southeast 14th Avenue and Belmont Street.

Kahn doesn't believe the drivers who failed to stop are explicitly or consciously racist. Instead, far more subconscious biases are at play, she said.

"Driving is a situation where you're processing a lot of information," Kahn said. "It's in those situations where the most subtle and implicit biases can impact decision-making."

In focus groups, black pedestrians backed up the findings anecdotally. Some said they had wildly different experiences crossing alongside a white friend than alone.

The researchers also found that drivers rarely stopped for any pedestrian at all at an unmarked crosswalk, even though they are required to yield to pedestrians under state law.

A round of tests were conducted at the same intersection, but before city workers had painted a zebra-striped crosswalk. They found that the first car stopped less than 3 percent of the time, and only 18 percent of the time did any car stop before traffic cleared.

The research might suggest that drivers perceive stopping for any pedestrian to be optional rather than required, Kahn said. The addition of crossing signals or beacons could help dispel that sense.

"That would reduce the discretion and ambiguity, and that might lead to more equitable stopping," she said.

-- Elliot Njus

enjus@oregonian.com

503-294-5034

@enjus