The yearly traffic index is out and, no surprise, Seattle has some of the worst congestion in the nation.

Seattle drivers wasted 63 hours stuck in traffic last year, according to the study by Kirkland-based Inrix and Texas A&M Transportation Institute. That’s more than two and a half full days staring at the bumper in front of you. You’re also wasting about 28 gallons of fuel every year.

Tell us about what slows you down

Seattle is ranked the seventh worst congested city in America, slightly ahead of Chicago. Washington D.C. is the worst city to commute in. Drivers in the Beltway spend an extra 82 hours in traffic.

The capacity of Seattle’s roadways might be the biggest factor in why traffic gets so backed up, KIRO Radio traffic reporter Chris Sullivan explained. The Seattle Department of Transportation, which is studying ways to reduce congestion during an accident, previously reported that the city’s “hourglass” shape is one of the biggest constraints. The limited number of crossings over waterways, too, contributes to congestion even when there isn’t a crash.

But what about when there is a crash?

It’s not just geography that contributes to hours upon hours of traffic, KIRO Radio’s John Curley pointed out. Rubbernecking, he believes, is the biggest culprit to traffic congestion. A simple fender-bender can cause miles of backup, not only for lanes in the same direction, but for the opposite direction.

Curley’s theory isn’t far off from the truth, Sullivan said. Last week, for example, a two-hour backup was caused by a crash that occurred in lanes going the opposite direction.

“We’re dealing with common variety fender-benders that really aren’t worth looking at,” Sullivan said.

Curley said the people slowing down to gaze at car crashes are those without anything better to do. If they had places to be, they wouldn’t give an accident a second thought.

All that time spent in traffic adds up though. The average Seattle-area resident spent $1,491 on traffic last year. That number is based on the cost of delays and extra fuel consumption.

However, saying it costs people time and money to be stuck in traffic is assuming everyone has better things to do, Curley said. He would put his money on that extra 40 minutes sitting in the car would be wasted anyway.

The good news for drivers is that the delays and costs have not gone up significantly over the last 10 years, according to the study. Seattleites have been wasting around 60 hours and $1,500 a year because of traffic since about 2003.

“I think it’s pretty clear people are frustrated,” Tim Lomax, a co-author of the report at the institute, told USA TODAY. “It’s not just the average time. It’s that you have to plan around 45 minutes for a trip that ought to take 15 or 20.”

The study forecasts that the average delay for Americans will grow to 47 hours by 2020. The total delay will climb to 8.3 billion hours.

KIRO Radio’s Chris Sullivan and MyNorthwest’s Kipp Robertson contributed to this report.