At a handful of Bay Area freeway on-ramps, all some drivers can do is grip the wheel, hit the gas and hope.

Ideally, on-ramps include a few key features: a lengthy approach that allows drivers to get up to highway speed to make the merge, and good visibility to see who’s closing in from behind.

But many ramps around the region are just too short. Drivers are faced with unpredictable options as they gun it to 65 mph — or faster — while trying to avoid being run off the road or getting crushed by a barreling big rig. Horsepower is key, as is a neck with a strong swivel.

While no one has studied the Bay Area’s shortest on-ramps, data compiled by the California Highway Patrol appear to confirm the danger of a few notorious spots.

Take the westbound ramp from Treasure Island and Yerba Buena Island onto the Bay Bridge, where drivers encounter a stop sign and then a succinct merge of roughly 135 feet. The area saw 665 wrecks from 2002 to 2013 — roughly one a week — with 311 people injured and one killed, the CHP said.

“There’s not enough acceleration after the stop sign,” said 65-year-old Bill Dani of Berkeley.

He enjoys stopping by Treasure Island, which is home to some 2,000 people, to take in the sweeping view of San Francisco. But he doesn’t enjoy the re-entry. When he heads back onto the freeway, he said, he waits as long as it takes for the lane to completely clear so he doesn’t “make an accident.”

Back in September, somebody did make an accident.

Six cars piled up on a Sunday morning at the westbound on-ramp toward San Francisco. No one was seriously injured, but the crash had a ripple effect and jammed up bridge traffic for hours. Irritated weekend drivers stood beside stopped cars back at the toll plaza.

Another trouble spot is the ramp from 29th Avenue to southbound Interstate 880 in Oakland, a popular route for motorists leaving Alameda via the Park Street Bridge.

Try, try again

The merge is about 250 feet long and is also an off-ramp, which complicates things considerably. Exiting drivers pack the right lane, creating a nasty crisscross of cars. Stymied motorists trying to get onto the freeway sometimes stay in the merge lane, take the exit, drive around the block and make another go at it.

Back to Gallery Bay Area’s riskiest on-ramps keep hearts racing 7 1 of 7 Photo: Brant Ward / The Chronicle 2 of 7 Photo: Michael Macor, The Chronicle 3 of 7 Photo: Michael Macor, The Chronicle 4 of 7 Photo: Michael Macor / The Chronicle 5 of 7 Photo: Michael Macor / The Chronicle 6 of 7 Photo: Michael Macor, The Chronicle 7 of 7 Photo: Michael Macor / The Chronicle













According to the CHP data, there were 163 crashes in the area of the ramp between 2002 and 2013. Fifty people were injured and one person died.

“It’s dangerous,” said 23-year-old Hazel Rodriguez, who works at a coffee shop in Oakland and drives home south on Interstate 880. She noted that the merge unfolds after a sharp right turn from 29th Avenue, forcing her to nearly stop before she floors it into the flow of whizzing traffic.

“There isn’t any time,” she said. “You have to go faster than the other drivers or hope you get let in — which doesn’t happen.”

Jerry Lester, a 78-year-old retiree from Berkeley who once lived in the area, said, “You have to time it exactly. It gets a little scary sometimes. If somebody doesn’t know who has the right of way, you have problems.”

Lester is among a number of Bay Area residents who choose to simply avoid such ramps. He’s now “found a new way to get on the highway” whenever he visits his old Alameda neighborhood near the Park Street Bridge.

CHP officials stressed that the crash stats do not differentiate between causes for the wrecks — which could include inclement weather and just plain bad driving.

Drivers responsible

“Nearly every collision that occurs on our freeway system is avoidable, and is due to someone operating their vehicle while neglecting their duty to drive safely, or in violation of a traffic law,” said Officer Daniel Hill, a spokesman with the CHP’s Golden Gate Division. “Ultimately, each driver is responsible for operating his or her vehicle in a safe manner.”

The I-880 on-ramp, though, is not an anomaly. Many freeways around the Bay Area were engineered in the 1930s, ’40s and ’50s.

Some cities later filled in the tight nooks within the network of roadways with homes and businesses, making modifications difficult without crews ripping through neighborhoods to make room for longer ramps or new configurations.

But relief is coming — at least in some spots.

San Francisco has long vowed to improve both the westbound and eastbound Treasure Island on-ramps, and in January 2014 construction began on an estimated $98 million system of elevated ramps that will also include a new westbound exit. Work is scheduled to be completed next year.

Outdated designs

Caltrans officials said they are aware of other problematic on-ramps around the Bay Area, though many were replaced with modern and efficient diamond-shaped flyovers after some older versions were damaged by the Loma Prieta earthquake in 1989.

One outdated design — of which dozens remain around the region — is the cloverleaf interchange. The space-saving model was popular in the 1950s, but is now recognized by experts as hazardous because drivers circling toward a freeway must slow down to a crawl moments before they are kicked into the speeding flow of the lanes.

This is precisely the dynamic in San Mateo at the cross of El Camino Real and Highway 92. Drivers must exit to the right, sweep around and immediately merge. Much like the Interstate 880 mess, freeway motorists are simultaneously crossing over toward the off-ramp just ahead.

Just one of the four cloverleaf merges at the San Mateo interchange saw 135 crashes between 2002 and 2013, resulting in 70 injuries and one fatality, the CHP said.

Engineers are in the design phase of replacing the interchange, with work slated to begin as early as January 2017, said Bob Haus, a Caltrans spokesman.

“If there are any (on-ramps) that are flat-out dangerous, we would have to shut them down,” Haus said. “It’s a matter of speed and making sure you are aware of your surroundings — the common-sense driving rules.”

Potential fixes

UC Berkeley Professor Alexander Skabardonis studies ways to improve outdated highway designs with better signs and new technology to warn drivers.

With on-ramps, “you have a zipper effect. It does not require much effort to merge if both vehicles are moving at the same speed. But not with different speeds,” he said. “The modern highway interchanges are not cloverleafs. Perhaps it is because of these issues.”

While Caltrans evaluates on-ramps that may need replacing, drivers will have to make do. Some consider the ramps to be merely another challenge of traveling in the Bay Area.

“I’ve been taking it so long, it doesn’t freak me out,” said Veronica Gallardo, who routinely merges onto southbound Interstate 880 from Alameda.

“You have to step on the gas,” she said. “And you have to have quick reflexes.”

Evan Sernoffsky is a San Francisco Chronicle staff writer. E-mail: esernoffsky@sfchronicle.com Twitter: @EvanSernoffsky

What’s not working

Issue: Some on-ramps to Bay Area highways and interstates are too short. Drivers don’t have enough distance to accelerate and merge into the flow of traffic. Hundreds of crashes happen every year due in part to the short ramps, which many drivers have learned to avoid.

What’s been done: Caltrans is working to update several antiquated on-ramps around the Bay Area, including an outdated interchange between Highway 92 and El Camino Real in San Mateo. Meanwhile, San Francisco is improving the harrowing ramps onto the Bay Bridge from Treasure Island and Yerba Buena Island, with construction due to be completed next year.

What you can do: To report dangerous drivers, call the CHP at (800) 835-5247. To alert Caltrans to a dangerous on-ramp, call (916) 654-2852. To tell the Chronicle Watch staff about your experience with a short on-ramp, e-mail chroniclewatch@sfchronicle.com.

Chronicle Watch

If you know of something that needs to be improved, the Chronicle Watch team wants to hear from you. E-mail your issue to chroniclewatch@sfchronicle.com, or reach us on Twitter: @sfchronwatch.