Sure, a car-free Market Street is nice, particularly for Muni riders and cab drivers who now have much of SF’s busiest thoroughfare largely to themselves. But doesn’t closing one street to most traffic just create gridlock on the nearest neighboring streets?
Traffic data company INRIX says the answer is yes, at least in the case of Mission Street, the next most obvious alternative to Market Street between Van Ness and Steuart. But the company also notes that the difference is marginal and not that dire compared to how the closure has juiced SF public transit.
INRIX, which largely extrapolates data from drivers using its own app, compared traffic activity from Mission, Howard, and Folsom Streets during rush hour periods (7 a.m. to 9 a.m. and 5 p.m. to 7 p.m.) for a period of roughly two weeks before the closure in January and about three weeks later in February.
Traffic went up, but not by much.
- Traffic on Howard Street actually declined during the survey period, with average speeds increasing by as much as nine percent, depending on the hour. Only around 7 p.m. did research detect any decrease in speeds on Howard, but a one percent decrease in speed.
- Folsom Street performed even better, with no decline in average speeds at all and an increase up to 10 percent during some hours.
- Mission Street bore the brunt of the shift, with average speeds declining up to six percent, and speeds down in almost every hour except for northbound lanes between 7 a.m. and 8 a.m., which were flat.
INRIX says the Market Street closure had “a benign impact on travel speeds.” The firm points out that the combined results are a mere one percent decrease speed in the morning and zero percent in the afternoon.
As for a slightly more sluggish Mission Street, the firm argues that the results are negligible compared to the benefits for Market transit users, comparing the experiment favorably to similar closures in New York City. San Francisco Examiner reports that buses and streetcars on Market Street are performing more reliably now.
It’s also important to note that while INRIX’s app-driven data is handy, it doesn’t represent every driver on the road, and the first three weeks don’t represent the full effect of a new policy. The city will release more comprehensive studies in the future
For the record, the San Francisco Municipal Transportation Agency holds that Market Street was not particularly busy these days, only averaging up to 400 vehicles per hour during rush hour, whereas Mission was already the busier byway with an average of more than double that.