What WBUR missed in its series on traffic

All this week the public radio station WBUR has been publishing articles about traffic congestion in Boston, spurred by the news that the City is the sixth most congested in the country. While the series has made some good points, including recognizing the reality of induced demand, but it has been overwhelmingly biased towards the car.

The bias starts with the premise of the series: that Boston is the sixth most congested city in the United States. This comes from the Texas Transportation Institute, which is famous for it car focus. They probably think that Venice is impossible to get around in because there are no cars.

Now, if one reads the report, which is TTI’s annual Urban Mobility Scorecard, the single-minded focus becomes clear: congestion for TTT is purely a matter of uninhibited speed — how long a trip takes in traffic versus how long it takes at “free flow.” Well, if all you have is a hammer (or videos of Jeremy Clarkson yelling “Power!”), every problem is going to look like a nail.

Or, as Stephen Lee Davis at Transportation for America puts it: “There’s a direct connection between how we decide to measure congestion and the resulting strategies for addressing it.”

The consequences of trying to get cars to move through city streets as quickly during the day as in the middle of the night can be measured in many different ways, but when it comes right down to it, the only measure that matters is the number of deaths. According to Vision Zero Boston there were 79 people killed in crashes between 2010-2014 on Boston’s streets, with the percentage of pedestrian fatalities on the rise — however, 1,279 pedestrians and cyclists needed some form of medical care as a result of being hit by cars in 2014.

Most of these crashes were on Boston’s arterial streets, where people are eight times as likely to die from a crash, regardless of mode. It is not just a coincidence that arterial streets are explicitly and deliberately designed to move large numbers of cars quickly through or to an area. Increasing roadway capacity and speeds will result in more deaths.

Davis points out that measuring congestion by roadway delay only is also blind both to the number of people moving and people who commute by transit, bike or walking:

Another major shortcoming is that roadway delay focuses only on drivers — not commuters as a whole, ignoring the millions of people opting out of congestion entirely by using various other options like transit, walking or biking or skipping the trip by telecommuting.  Under a roadway delay measure, if a city has made investments like these that allow a large share of its commuters to skip roadway congestion entirely, it can be rated the same as another city where the average delay on the roads is the same, even if 100 percent of that second city’s commuters are stuck in traffic.

Delay is also blind to how many people a corridor is actually moving — it only looks at the number of vehicles. Should two similar corridors, where the first moves three times the amount of people as the second because of a carpool requirement or a lane dedicated to high-capacity transit, have the same scores for delay just because the travel speed is the same?

Ultimately, what the articles about car commute times and congestion all miss is that cars are singularly unsuited for urban transportation.


Via UrbanData on Twitter.

As the graph makes clear there is an upper limit to how many people can go through an area in an hour in single-occupancy vehicles. With jobs in Greater Boston concentrated in four compact locations — Back Bay, Downtown, Seaport, Kendall Square — it means that the limit has been reached.

All of the “smart data”, all of the ridiculous claims made about self-driving cars, cannot change those numbers anymore than driving an electric vehicle changes the fact that the vast majority of electricity in this country comes from coal. They cannot change the fact that traffic comes from cars on the road.Shared streets, busways, transit signal priority, upgraded rail systems and other investments in walkability, cycling and transit is the way to beat congestion.




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