Construction makes terrible San Francisco traffic even worse, says study

Requests for permits for traffic slowdowns around San Francisco construction projects have doubled in the last 10 years, and buildings in progress diminish cruising speeds on nearby streets by up to nine miles per hour, according to the San Francisco Examiner.

The latter number comes by way of Washington state-based traffic data firm INRIX, which conducted a review of San Francisco streets at the newspaper’s request.

San Francisco Examiner reporter Joe Fitzgerald Rodriguez writes:

Inrix found significant traffic slowdown near corridors with comparably higher numbers of construction sites, based on a map of permitted construction assembled by the Department of Building Inspection and traffic speeds compared before and after construction began. Inrix used Market Street as a control. [...]

Inrix offered the data with caveats that it is difficult to account for every other variable on city streets, like lane eliminations or road construction. Still, the numbers were stark.

Most affected streets seem to have lost about four miles an hour on average at commute times, with some slowing to speeds as glacial as four miles per hour at some times of the day.

INRIX is the same firm that declared San Francisco traffic the fourth worst in the world in February and the third worst worldwide in 2016, so they have some experience with San Francisco street snarls.

Here’s the rundown of the slowdowns at the worst times for key commutes before and after major nearby construction began:

• First Street (southbound between Market and Harrison), 10 a.m.: Average traffic speed was 14 mph in 2015, 10 mph today
• Howard Street (south between Embarcadero and 13th Street), 2 p.m.: From 14 mph to 10 mph
• Harrison Street (south between Embarcadero and Division), 6 a.m.: 18 mph to 14 mph
• Sixth Street (south between Market and Townsend), 9 a.m.: 14 mph to 10 mph
• Bryant Street (north between Division and Embarcadero), 9 a.m.: 14 mph to 10 mph

The paper does note that other factors over the course of two years may affect traffic too, including the increased proliferation of ride-hailing apps. Check out the San Francisco Examiner story for more.

Photo by Aaron Kohr/Shutterstock

• Analysis: Traffic Slowing Construction [Examiner]
• SF Has Fourth Worst Traffic [Curbed SF]
• SF Third Worst In Traffic [SFist]