EL CERRITO — When his work schedule changed a couple of years ago to include shifts on Saturdays and Sundays, tattoo artist Owen Partridge figured the silver lining would be a traffic-free commute.

“I thought, ‘Oh this will be easier,'” said Partridge, whose trip to work takes him down the often traffic-choked Eastshore Freeway from his home in Vallejo to shops in Berkeley and San Francisco.

But Partridge has come to learn the same lesson as countless Bay Area drivers who spend Monday through Friday slogging through some of the worst congestion in the country, and look to their weekends for relief from the grind: Traffic here doesn’t take a day off.

“Saturday is really like any other commute day,” Partridge said.

On some of the Bay Area’s busiest freeways, the bumper-to-bumper traffic of weekend warriors can rival the worst of the work-week commute, according to data this news organization analyzed from the traffic analytics firm INRIX.

Generally speaking, of course, weekends tend to see less severe traffic than weekdays. Still, drivers expecting smooth sailing on their days off can be in for a rude awakening.

Take one especially painful stretch of the Eastshore Freeway that Partridge drives on the days he doesn’t opt for BART.

San Francisco-bound commuters pack the road bumper-to-bumper before dawn, consistently earning the freeway a spot near the top of annual rankings of the worst drives in the Bay Area. At the slowest point of the weekday morning rush, drivers average 19 mph between Albany, where Interstates 80 and 580 meet, and the Bay Bridge toll plaza. They average 18 mph coming the opposite way during the peak afternoon hours.

Weekend traffic is far better during the early mornings, but can be nearly as bad through the afternoons, when average speeds reach as low as 26 mph in both directions.

Looked at another way, drivers headed toward San Francisco are more likely to hit traffic on that stretch of Interstate 80 during weekends. The freeway is considered congested — meaning drivers’ average speeds are less than 35 mph — for nine straight hours on Saturdays and Sundays, between 11 a.m. and 7 p.m. On weekdays, that’s the case seven hours per day, mostly during the morning rush.

“You don’t get a break,” said Sonja Kaufman, a teacher from El Cerrito who avoids the freeway as much as she can. “It is usually brutal.”

Simple cause: Too many cars

Sporting events cause some weekend traffic jams. Construction projects cause others. And weekend drivers may not move as efficiently as their weekday counterparts: Whereas commuters know the mergers and bottlenecks of their route like the back of their hands, there are more visitors among weekend drivers, who may not be as familiar with the roads. Weekend drivers also are more likely to pay with cash at bridge tolls rather than using FasTrak.

On Sunday just as Wednesday, the reason for traffic is the same: There are more cars on the road than space to move them — more beachgoers, hikers, Little League players, restaurant diners and, of course, weekend workers.

“There is just so much demand there, all days of the week,” Trevor Reed, an INRIX transportation analyst, said of the Bay Area.

Even though there are fewer cars on weekends overall, Reed said, “You’re still hitting that tipping point where you’re causing everything to fall apart.”

The Bay Area News Group analyzed data from INRIX that shows the average speed of cars along several busy Bay Area freeway corridors for every hour on a typical weekend and weekday, pulled from anonymized data the company collects from car navigation systems.

Some routes delivered the relief weekend drivers might hope for. Highway 101 between Interstate 880 in San Jose and Highway 92 in Foster City can be miserable at rush hour, with average speeds falling to just 22 mph along the 34-mile stretch during the southbound afternoon commute. Traffic flows almost freely on the weekends, however, with average speeds never falling below 60 mph.

For other routes, even if the weekend wasn’t as bad as the work-week rush, it is still no picnic.

Eastbound drivers traveling through San Francisco toward the Bay Bridge creep along at just 19 mph on average during the worst hours of Saturday and Sunday afternoons, between the Highway 101/Interstate 280 interchange and the point the bridge leaves the city. Compare that to an average of 12 mph on weekday afternoons, or 61 mph when traffic is lightest in the middle of the night.

On Interstate 680, eastbound drivers slow down to an average speed of 31 mph on weekend afternoons between Highway 262 in Fremont and Highway 84 in Sunol. That’s more than twice as fast as they manage during the worst of the afternoon commute, but less than half as slow as free-flowing traffic speeds.

One question that is hard to answer is whether weekend traffic is worse now than it used to be. INRIX’s data only goes back a couple of years, which don’t show major changes.

But there are signs that it might be: Weekday traffic congestion rose 80 percent from 2010 to 2017. And data from the Metropolitan Transportation Commission shows a typical weekend day this year now sees more than 40,000 additional people crossing Bay Area bridges compared to 2010.

“Before, you could depend on weekends being easy,” said Laura Sandlin, who lives in Antioch and has cut hair at an El Cerrito barber shop for more than 30 years. Traffic is a problem “all the time” now, she said.

Transit suffers on weekends

While the obvious solution to traffic is to get people onto public transportation, luring Bay Area drivers out of their cars can be even tougher on the weekends.

“Our transportation system is really built for the commute,” said Arielle Fleisher, transportation policy director at the urban planning think-tank SPUR.

Public transit agencies typically run less frequent service, or eliminate certain routes entirely, over weekends and holidays, which tend to have fewer riders.

That leads people to view mass transit primarily as a tool to get to and from work, Fleisher said, and less as something they can use to get to friends’ houses or the beach on their days off.

“It’s really easy to fall into your default of your car on the weekends,” she said.

Then there is the problem of destinations.

Chris Lepe, regional policy director for at the transportation advocacy nonprofit TransForm, said the region’s public transit systems “are not targeted toward the kind of destinations people want to go to on the weekend.”

The Bay Area’s buses and trains funnel a lot of people into job centers such as downtown San Francisco from Monday to Friday, but destinations tend to be much more scattered on the weekends, and might include parks or beaches with few options for transit.

Then there are the longer weekend trips people take that would be difficult to do any day of the week without a car, given the complex, often poorly connected, a web of more than two-dozen public transit agencies that struggle to knit the Bay Area together.

Lepe, as you might imagine, is a pretty avid transit user: From his home in San Jose, he regularly takes Caltrain to San Francisco and Amtrak to the East Bay. But if he wants to visit friends or go camping in Sonoma County over the weekend, he said, “There isn’t a good option.”

So Lepe winds up driving instead — and often getting stuck in traffic.

There’s no sign that the factors creating weekend traffic jams will be easing any time soon. As long as money is tight and transportation agencies need to prioritize spending, devoting money to improving commutes rather than weekend trips may not be a bad thing — after all, it would affect more people on more days each week, Lepe said.

“What makes the most sense in terms of bang for the buck?” he said.

So drivers will continue to jam the Bay Area’s clogged freeways on Saturdays and Sundays, and try to find ways around weekend congestion just as they do Monday through Friday.

Sandlin, the El Cerrito barber, makes sure to take her weekend trips early: Get through the Eastshore Freeway by 11 a.m., she says, or you’re in for trouble.

Once the traffic gets bad on weekends, Sandlin has an even more extreme workaround: To avoid the slog to and across the Bay Bridge when she drives to visit her children in San Francisco, she drives over the Richmond-San Rafael Bridge and the Golden Gate Bridge. Tolls means the trip winds up costing Sandlin more than twice as much, but she says the route is worth it.

“You’ve got to do what you’ve got to do, so you don’t have to sit” in traffic, she said. “It’s just too frustrating.”