Where's the Worst Traffic in the Bay Area?

Bay Area drivers spent 22 percent more time on congested freeways in 2015 than they did the previous year and 70 percent more than in 2010. The Bay Bridge corridor is the worst offender.

That means vehicles traveling northbound from Highway 101 -- at the Interstate 280 interchange -- to the Yerba Buena Island Tunnel spent a total collectively of 13,000 hours a day traveling at speeds less than 35 mph, according to a report released by the Metropolitan Transportation Commission Monday.

That 6-mile stretch is now the most horrendous commute in the Bay Area, moving up from fourth place in 2014.

It had the dubious honor of displacing the westbound Interstate 80 drive from Highway 4 in Hercules to Highway 101 in San Francisco, which is now the second-worst commute in the region. But the MTC notes that the congestion on the westbound I-80 drive is unprecedented: It typically lasts from 5:35 in the morning to 7:50 at night -- the first time routine congestion on any Bay Area freeway segment has not been relieved by a break in the middle of the day.

According to MTC spokesman Randy Rentschler, since the number of lanes on the Bay Bridge is already set, there's not much the commission can do to alleviate the traffic crunch.

“Other than BART and more ferries and buses, there's very little we can do on that roadway,” Rentschler said. “The bridge is five lanes. That's what the bridge is going to be. It's very unlikely we're going to build another one."

The report also shows a jump in congestion in the South Bay.

The drive on Interstate 680 north and 280 east from East San Jose to Cupertino soared up the list. It went from being the 20th most congested freeway in 2014 to the third in 2015.

Rentschler attributes that change to the increase in employment in the South Bay and San Francisco.

“Both San Francisco and down south in Santa Clara County, Silicon Valley, are big job generators and you can see the traffic congestion as people seek to reach those job locations,” he said.

In 2015, employment in the Bay Area reached an all-time high of 3.7 million, almost half of it in San Francisco or Silicon Valley.  Two out of three Bay Area commuters drive solo to work, according to the MTC.