The Pre-Dawn Patrol

Bay Bridge toll plaza
Photo credit Getty Images

SAN FRANCISCO (KCBS Radio) -- Drivers are arising earlier and earlier to hit Bay Area freeways, upending traditional commute patterns in the process.

Data compiled for KCBS Radio by the Metropolitan Transportation Commission provide stark evidence of this shift. The number of vehicles passing through the toll plaza of the San Francisco-Oakland Bay Bridge between 3 AM and 4 AM has jumped 50 percent since 2015 and 11 percent in the last year.

For the hour between 4 AM and 5 AM,  westbound Bay Bridge crossings have skyrocketed by 80 percent since 2015 and by 35 percent in the last two years. Meanwhile, what was once considered an early commute hour--5 to 6 AM--has seen a 16 percent decline in crossings since 2018, and the 6 to 7 AM hour registered a 6 percent decline.

For the purposes of this report, the MTC compared numbers from a single Wednesday in May (May 15th this year) with a corresponding Wednesday in earlier years. MTC experts felt the methodology would provide an "apples to apples" comparison, free of the influences of holidays, school vacations, or other factors.

While the Bay Bridge carries more traffic than any other bridge in the region, other spans also showed clear evidence of a commute time shift. At the Richmond-San Rafael Bridge, crossings in the 5 AM to 6 AM hour are up 29 percent since last year and 88 percent since 2015, while crossings between 6 AM and 7 AM fell by 24 percent in the last year and by 13 percent since 2015.

The San Mateo Bridge has seen traffic in the 4 AM to 5 AM hour jump by 57 percent since 2015, while 6 AM to 7 AM volume is down by 4 percent.

The Dumbarton Bridge registered an 8 percent decline in 6 AM to 7 AM traffic over the last year, while volume an hour earlier rose by 6 percent.

The  time-shifted commute has caught the attention of longtime observers like KCBS Radio midday traffic anchor George Rask, who first covered the region's traffic scene in 1982. "Where we used to see traffic peak at around 6:30 to 7:30 in the morning, that's no longer the case. Numbers are peaking in the 5 o'clock hour," said Rask.

And while this report focuses on Bay Bridge toll-crossing numbers, Rask sees a bigger picture. "Coming from the Central Valley, that's a commute, where in the 3 o'clock hour and the 4 o'clock hour, we see more and more congestion. One of the ways we monitor conditions here is we use Caltrans sensor data. And we see red, which is an indication of below 30 mile an hour traffic, in the 4 o'clock hour." 

While commuters rise earlier and earlier to hit the roads, the people who build and maintain those roads are having to adjust. Caltrans has traditionally scheduled major paving projects for the overnight hours, aiming to have lanes re-opened in time for the morning commute rush. At one time, that meant requiring contractors to finish their work by 6 AM.  In recent years, it's been a 5 AM target.  These days, even that is likely to cause a major backup.

"Adjustments have to be made in the way that we perform work. There have been improvements in the industry over the years. Better lighting, better safety, better materials that we're using that can cure faster. Those types of things help but it's still a big challenge for our Caltrans teams and the contractors to get the work done within the time that's allotted out there," said  Bart Ney, chief of Public Affairs for Caltrans in the Bay Area.