It’s not your imagination, the lack of a second cup of coffee or general crankiness. The morning commute in the Bay Area is getting worse.

Not only that, but the backup is far more persistent. It begins before dawn and lasts through mid-morning, and a driver who rises early with designs on breezing to the office is no longer guaranteed safe passage.

An analysis of the number of vehicles that crossed the Bay Area’s seven state-owned bridges in October shows that traffic is up sharply when compared with the same period five years ago, and the growth is continuing.

The jump is particularly noticeable from 5 to 6 a.m. on the four backbone bridges hauling westbound commuters to San Francisco, the Peninsula and Marin County, according to the counts of toll-payers collected by the Bay Area Toll Authority.

“It’s terrible everywhere — and at rush hour, it’s just awful,” said Cherrise Lewis, 57, an Uber driver who’s a San Francisco native but now lives in Emeryville. “You used to be able to gauge the traffic, to know when you could go, but now it’s busy all the time.”

All bridges affected

On the Bay Bridge, the Bay Area’s busiest, the number of San Francisco-bound morning drivers — those traveling between 5 and 10 a.m. — has grown by 11 percent since 2010 and roughly 2 percent in the past year.

The San Mateo Bridge has experienced a 29 percent morning jump over the past five years, with a 4 percent rise in the past year alone.

Traffic on the Dumbarton Bridge is up 27 percent over five years and 3 percent in the past year. And the Richmond-San Rafael Bridge has seen a 21 percent increase since 2010 and a 2 percent rise in the past year.

The numbers reflect, in large part, commuters who are trying to beat the rush on the early side — a strategy that’s weakening with popularity.

Sal Castaneda, KTVU’s traffic reporter, has noticed the commute creeping into 5 a.m. territory. The Bay Bridge metering lights used to switch on for the morning at 5:45 a.m., but now it’s more like 5:30 a.m.

In the past, a small, quickly cleared stall or collision on the bridge at that hour wouldn’t have a lasting effect.

“Now,” he said, “the 5 o’clock hour is like the 6 o’clock hour used to be. A broken-down car at 5:30 can affect traffic until 10 a.m.”

The Bay Bridge has seen a whopping 75 percent rise in the number of bleary-eyed commuters passing through the toll plaza between 5 and 6 a.m., with an 11 percent increase over the past 12 months.

More commute west

The five-year jump during that same early hour is 81 percent on the San Mateo Bridge, 61 percent on the Dumbarton and 43 percent on the Richmond-San Rafael Bridge.

The surging economy, with the bulk of the jobs in San Francisco and on the Peninsula, is driving the growth in traffic, said Michael Cunningham, senior vice president for public policy at the Bay Area Council, a business group.

“The traffic is all over,” he said. “But wherever you are in the Bay Area, the concentration in job growth is mostly to the west. So we see a traffic increase in the westward direction, getting worse the closer you get to San Francisco and Silicon Valley.”

The steep rise in early morning drivers is no surprise, Cunningham said, a matter of necessity rather than choice.

“The Bay Bridge can only handle a certain number of cars per hour,” he said. “During the peak hours when the metering lights are on and the bridge is full, nobody else can get on it.

“As jobs have been getting added in San Francisco or on the Peninsula,” he said, “the choice has been either to go in early while there still is some capacity on the bridge — and that time keeps getting pushed earlier and earlier — or go in later, or go in during peak and just wait in line.”

Castaneda recently asked his followers on social media if they’ve been starting their commutes earlier. An overwhelming number said yes.

“They said you’ve gotta get out there before it gets too crowded or anything happens that backs up traffic,” he said.

Evening drive heavier, too

Figures from the Carquinez and Benicia-Martinez bridges, which collect tolls from eastbound motorists, reveal increased traffic during the evening commute home — from 3 to 7 p.m.

At the Carquinez span in Crockett, the number of vehicles in October was up 8.4 percent since 2010 and 2.7 percent in the past year. The Benicia bridge saw 10.2 percent more traffic than five years ago and a 3.4 percent increase over the past year.

Continuing the trend, the biggest increases in the evening commute across those bridges were seen between 6 and 7 p.m.

“It’s starting earlier and earlier,” Cunningham said, “and ending later and later.”

Michael Cabanatuan is a San Francisco Chronicle staff writer. E-mail: mcabanatuan@sfchronicle.com Twitter: @ctuan