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D.C. crash-mapping gets boost from firm that can also help identify dangerous hotspots

Mapbox, Inc., a tech firm with offices in D.C., is helping Washington map its crashes and traffic flow. (Screen grab from Mapbox, Inc. blog)
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A tech firm is helping D.C. map crashes with a degree of specificity that would allow transportation officials to identify hotspots where there are not only a lot of accidents but a higher rate of them.

Mapbox, Inc., which has U.S. offices in Washington and San Francisco, partnered with D.C. to take open-source data from the city government and mash that together with other sources of data, such as smartphone use, to create a dynamic map that would show crashes and their correlation with traffic flow.

This map shows the worst D.C. intersections for pedestrians

What’s more, the data would account not just for vehicles, but for pedestrians and bicycles, according to company and city officials. They said that by also collecting feedback in real time, the mapping could allow for a more efficient view of congestion that could improve navigation and traffic control.

“They took that open data set for crashes and were looking for other correlations with other data they have at Mapbox,” said Jonathan M. Rogers, a policy analyst with the District Department of Transportation. He said the software is building on the sort of mapping that DDOT has been doing for some time.

The mapping can show the frequency of crashes from Census tracts down to street level. In Census block 1004, for example, there were 187 crashes, including 10 involving bicyclists and pedestrians in the vicinity of Truxton Circle. There were also three fatalities in the area.

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Rogers said the city is hoping to use the mapping to identify those areas that, for whatever reason, have the highest rate of crashes based on traffic volumes, not just the most crashes, and figure out what can be done to reduce the rate. “It can put it in a more useful context,” Rogers said. And that could help safety officials prioritize ways to intervene.

A blog post on the company’s website notes that the mapping shows about what you’d expect in some ways: the busier the street, the more crashes, and the more cross streets on an artery, the more crashes, and so on. But it also found that roads with higher observed speeds didn’t necessarily have more crashes than those with slower-moving traffic, perhaps because those arteries are also more isolated.

“It’s actually making true sense of the data,” Mapbox spokeswoman Christina Franken said in an interview. Franken, who was in town for the Smart Cities Week conference this week, said the firm chose D.C. because of the amount of open-source data already available here.

The firm, whose goal is to change the way people move across cities, also is working with Bloomington, Ind.; Melbourne, Australia and the West Midlands metropolitan region in Britain. It’s also setting up D.C.’s enhanced mapping for free, basically performing an open pilot program to demonstrate to other government officials and transit organizations what it can do. You can check out their maps in a company blogposting here.

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