Traffic really is getting worse in San Francisco and the Silicon Valley. "Congested delay"—time spent in traffic moving 35 miles/hour or less—in the Bay Area increased 22% last year to an average of 3.2 minutes/commuter each weekday (up from 2.7 minutes the year before), according to data from the Metropolitan Transportation Commission. This is the Bay Area’s highest level of congested delay ever and about 70% higher than 2010.

The culprit? Employment reached an all-time high of 3.7 million jobs last year, the population rose to 7.6 million with one out of four area residents living in Santa Clara County. Jobs still remain far from affordable housing.

The worst congested roadway last year was the six-mile commute heading out of San Francisco in the afternoon along US 101/I-280 toward Yerba Buena Island. This commute supplanted the morning commute westbound I-80 from Hercules to San Francisco, now the second-worst commute.

Among those new to the top 10 list are the morning drive along southbound I-680 and northbound I-280 from East San Jose to Cupertino, the afternoon drive along northbound I-880 from Fremont to Hayward and the afternoon commute along northbound US 101 from Menlo Park to Foster City.

Traffic is increasingly affecting developers' decisions and many are choosing projects within city cores, near mass transit and/or close to major employers.