ANTIOCH -- Theresa Cuevas has a simple message for drivers on James Donlon Boulevard: Slow down.

During a vigil last week marking the two-year anniversary of a crash that took the life of her 19-year-old son Pablo Garibay, the Antioch woman spontaneously stood in the shoulder of the four-lane thoroughfare to urge passers-by to drive cautiously.

"People drive too fast through here and they don't even care," Cuevas said. "There's a park area here, and crosswalks with children. They need another stop light or stop sign or something."

James Donlon between Lone Tree Way and Somersville Road has long been one of the more dangerous streets in Antioch, as some drivers travel the curvy four-lane road, often used as a commuter route, much faster than the posted 40 miles per hour. The three-mile stretch has a history of accidents: drivers striking trees, soundwalls, medians, power poles, even pedestrians.

Police Capt. Steve McConnell said a growing number of residents are complaining about drivers whizzing through Antioch streets, especially those in residential areas south of Highway 4. Drivers are using those streets that parallel the freeway, as well as James Donlon, to bypass highway construction, he said.

James Donlon is prone to accidents, McConnell said, noting that there was a collision involving a motorcycle on that road that caused serious injury last Monday.

There have been 10 major accidents on the road, but none fatal, since Garibay's fatal crash, Cuevas said.

Cuevas' message last week was twofold: urging traffic to slow down and telling the many youngsters at the vigil to promise not to drink and drive.

Dozens of Pablo Garibay's family and friends, many wearing T-shirts and hoodies that bore his picture, stood in the light rain Tuesday to remember the gregarious teenager.

Garibay was killed on March 19, 2011, when the Dodge Durango he was riding in hit a retaining wall on rain-slicked James Donlon near Nightingale, flipping on its side. He and a group of friends were leaving a party. The driver of the SUV, Rafael Madrid, was drunk.

Madrid pleaded guilty in November 2011 to gross vehicular manslaughter while intoxicated, and was sentenced to four years in state prison.

Those gathered at the vigil grieved in their own ways, some lighting candles or lanterns, others playing his favorite hip-hop song on their phones.

"He had his whole life in front of him, his dreams. He didn't deserve to die," his father, Jose Garibay Sr., said. A parent never expects to outlive his child, he said, noting it feels like being in a "dark room."

Ironically, Garibay's twin brother, Jose Jr., was delivering pizzas and crashed his car on James Donlon about 20 minutes before the fatal wreck, escaping injury, Cuevas said.

Ron Bernal, Antioch's public works director, noted the city last did conduct a traffic study on James Donlon in 2009, increasing the speed limit from 35 to 40 miles per hour -- the closest speed to what the "85th percentile of drivers" traveled.

If the speed limit was set below that mark, it creates an illegal "speed trap," he said.

As another safety precaution, James Donlon traffic lights were put in on Contra Loma Boulevard in 2004 and on Gentrytown Drive and G Street three years later.

Bernal, however, says his department hasn't received any complaints about James Donlon's speed lately.

"We used to get them because the speed limit was too low," he said.

Despite not having officers dedicated to traffic, police are doing directed enforcement in areas when possible, McConnell said.

"There is a small portion of those drivers that are going to speed regardless of what we do," McConnell said, adding that, while he was driving an unmarked police car on Thursday, he pulled over a driver on James Donlon that blew past at 55 miles per hour.

"We have to do what we can, when we can," he said.

Contact Paul Burgarino at 925-779-7164. Follow him at Twitter.com/paulburgarino.