For years drivers have complained and a new study confirms it: D.C. doesn’t handle unexpected traffic conditions well.

A new study by the Network Science Institute at Northeastern University ranks D.C. the worst of 40 major U.S. metropolitan areas in handling unforeseen road situations like inclement weather, sporting events or major crashes.

The study, published Thursday by the journal Science Advances, reported that D.C. is the least “traffic resilient,” or the least equipped to deal with road events that fall outside of typical traffic patterns.

Researchers examined unexpected weather events in the District, like the January 2016 incident when one inch of snow snarled traffic across the city, to reach its conclusion.

Researchers looked at cities like Los Angeles, which is notorious for traffic delays, and found that while traffic is an issue day-to-day, unexpected events on the road did not have a dramatic effect on a driver’s commute. This may be in part because the city has greater access to back-up roads, the study found.

Maksim Kitsak, an associate research scientist of physics in Northeastern’s Network Science Institute, said in a release that the findings are critical to shape future traffic policies because past policies have been modeled off of normal traffic conditions.

“Very little attention is being paid to questions of how road networks would respond if there were some major events like construction, sports games or very bad weather,” Kitsak said in the release. “We argue that both efficiency and resilience need to be taken into consideration.”