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A bicyclist enters Diablo Country Club in Diablo, Calif. on Thursday, May 16, 2013. Bicyclists heading to Mount Diablo, seeking a safer route, often take a shortcut through Diablo Country Club, where the roads are private. Residents are unhappy with the constant flow of bicyclist. (Jim Stevens/Bay Area News Group)

DIABLO -- Just as elite riders in America's most prestigious bike race prepare to zip past this affluent community on their way to Mount Diablo, residents here are pondering a ban on the outsiders who ride bicycles for recreation into their bucolic town.

The problem? More and more bicyclists are cutting through the unincorporated community -- along private roads, at that -- to reach Mount Diablo State Park. This allows them avoid narrow, busy and winding Diablo Road, the main route to the popular mountain climb.

These out-of-town cyclists blow through Diablo's ¿stop signs. They go too fast. And they ride two or three abreast across narrow roads, jeopardizing safety and movement in the small community, residents say.

Fed up, members of Diablo's road and police services board next month will discuss barring these cyclists at the town limits, unless they are visiting someone who lives there. The town's nearly 1,000 residents generally enjoy a quiet life among the large old trees surrounding their stately old homes, some of which have "registered" names.

"The most promising solution presented is to establish roads in Diablo as available only to local traffic," Richard Breitwieser of the Diablo Community Services District, wrote in a May 1 letter to Danville town officials. "Bicyclists who can't establish a Diablo residence or business purpose will be turned around."

Diablo resident Maryann Cella said the ban could be good for the community well as the cyclists themselves.

"I don't think it's elitist; I think it's a case of a government agency responding to the people and protecting public safety," she said. The district hasn't yet decided how to enforce the ban, but one possibility would be checking drivers' licenses at Diablo's few road entrances.

While Diablo's roads are privately maintained, they have no entry gates.

One Danville bicycle shop operator fears cyclists' lives are at risk if they are forced to use narrow Diablo Road to reach the mountain. Still, he is sympathetic to Diablo residents' complaints about unruly cyclists.

"We are talking about a road with high-speed traffic, no shoulders and limited sight views. It's horrible," said John Knowles of the California Pedaler about Diablo Road.

Hoping to avert the ban, Knowles is asking rude cyclists to shape up and "recognize they are guests" traveling through Diablo.

Traffic conflicts in Diablo have intensified with the growing popularity of Mount Diablo State Park among bicyclists looking for a challenging, scenic ride.

Lured by that same challenge, some of the world's top cyclists on Saturday will skirt the edge of Diablo as they race to the mountain summit finish in Stage 7 of the Amgen Tour of California.

Some Danville and Diablo residents said the solution to the safety dilemma is for Danville and Contra Costa County to join forces to widen about 1.5 miles of Diablo Road and add bikes lanes there.

"Danville and the county need to address the problem that Diablo Road is a wagon wheel road that hasn't changed since the days of the buggy," said Clelen Tanner, a Danville resident and cyclist. "I fear cyclists will be killed on it."

But it's not clear where the money would come from for such a solution, and officials say the widening may be impractical because of all the trees and dirt that would have to be removed. Another possibility is to build a separate off-road trail for cyclists and pedestrians, but there is doubt whether cyclists would use a path they would have to share with slower moving foot traffic.

Diablo residents are getting frustrated waiting for relief.

"It's a problem that is getting worse," said Cella, the Diablo resident. "Something needs to be done."

Contact Denis Cuff at 925-943-8267. Follow him at Twitter.com/deniscuff

Diablo facts

2010 Population: 964
Average House Value: $1 million
Avg. Income Per Household: $153,860
Median Age: 50.7
Land Area: 1.36 square miles

Source: 2010 census