Study Predicts Traffic Jam in Grand Avenue Extension

DIAMOND BAR â€”  The worst fears of residents’ groups have been confirmed by a study released by San Bernardino County officials that predicts serious traffic congestion resulting from the scheduled extension of Grand Avenue.

The Grand Avenue extension, which San Bernardino County officials hope to have open by April, will provide a direct route to the Orange and Pomona freeways from the rapidly growing but isolated community of Chino Hills. The extension has angered neighboring Diamond Bar residents, who believe it will exacerbate traffic problems in their community.

The study, prepared for the county by Kunzman Associates, a traffic engineering firm, projects that as a result of the extension, traffic on Grand Avenue in central Diamond Bar will reach 38,100 vehicles a day in 1991, 127% of the road’s designated capacity. Without the extension, the report states, 12,000 fewer vehicles would use the same stretch of road daily.

‘Hard to Swallow’

“We anticipated it would be bad, but it’s hard to swallow when you see it in black and white,� said Gary Miller, founder of Concerned Citizens for Diamond Bar Traffic Control, a watchdog group concerned with the impact of the Grand Avenue extension.

Gary Lawson, founder of the Stop Grand Avenue Expressway Committee, a more militant citizens group, said the study’s finding should bolster residents’ efforts to prevent the extension’s opening.

“It says exactly what we thought it was going to say: (the extension) is just going to ruin Diamond Bar,� Lawson said. “It adds fuel to the fire as far as I’m concerned.�

Traffic from Chino Hills can be expected to worsen, the report states, as the number of homes in the community grows from today’s 9,500 to almost 23,000 by 1996.

The increase in traffic congestion in Diamond Bar could be mitigated, the study states, by the addition of four traffic signals, the expansion of Grand Avenue and a section of Diamond Bar Boulevard to six lanes, and the creation of additional left-turn-only lanes at major intersections.

But, even with these improvements, traffic on Grand Avenue between Diamond Bar Boulevard and Golden Springs Road would still exceed the road’s capacity by 5%, with 47,100 vehicles a day expected by 1996, the study says.

“The mitigation measures are so inadequate, it’s ridiculous,� Lawson said. “It’s going to devastate Diamond Bar, there’s no other word for it. Property values throughout south Diamond Bar will be jeopardized. . . . The health and safety of Diamond Bar citizens will be jeopardized.�

Lawson said his group, in conjunction with a Chino Hills residents group concerned with traffic and excessive growth in that community, has consulted an attorney and plans to file suit against San Bernardino County to stop all development in Chino Hills and block the Grand Avenue extension.

The group would prefer to avoid a costly legal action, Lawson said, but this would only be possible if Los Angeles County Supervisor Pete Schabarum uses his authority to block the extension’s opening.

Miller, who was recently appointed by Schabarum to fill a vacancy on the Diamond Bar Municipal Advisory Council, said stopping the extension is not a realistic option.

“There’s no legal way to stop Grand Avenue from going through,� Miller said, noting that the extension has been included in plans for the region for decades.

Miller said the only way to minimize the adverse effects of the extension is for Schabarum to require stringent enforcement of an agreement that he said exists between the two counties.

Resolution Passed in June

The agreement is contained in a resolution passed last June by the Los Angeles County Board of Supervisors granting San Bernardino County approval to construct a section of the Chino Hills Parkway-Phillips Ranch Road project in northeastern Diamond Bar.

As a condition of its approval, the board stipulated that San Bernardino County officials complete the Chino Hills Parkway-Phillips Ranch Road project before opening the Grand Avenue extension. The board also required that San Bernardino County commission a traffic study to determine what type of measures to mitigate traffic in Diamond Bar and have those improvements finished before traffic can roll on Grand Avenue.

“Schabarum has to hold (San Bernardino County Supervisor Larry) Walker to that agreement, and those (mitigation) measures have to be implemented before Grand Avenue opens,� Miller said. “I have every reason to believe that he will make them abide by this agreement. I would be really surprised if he didn’t.�

Schabarum considers the resolution to be a binding agreement between the two counties and plans to enforce it, said his press deputy, Judy Hammond. However, Walker said that the promised mitigation measures will not be completed by Grand Avenue’s scheduled opening in March and that he has no intention of allowing the completed extension to go unused.

“We just can’t be in the position of spending $12 million to build a road and not being able to open it when there’s such a pressing need,� Walker said. “It is the opinion of our attorney, and of the Los Angeles County counsel, that there is nothing that can be done legally to stop the opening of Grand Avenue.�

Walker said Chino Hills Parkway and the various street improvements in Diamond Bar would be ready “within a very few months� of the opening of Grand Avenue. San Bernardino County has already set aside $400,000 to build improvements to help alleviate increased traffic in Diamond Bar, he said.

“We’re acting totally in good faith,� Walker said. “We’ve got major dollars set aside to build those roads, and we’re going to build them just as fast it can physically be accomplished.�

‘It’s Going to Be a Funnel’

But the prospect does not gladden Diamond Bar residents such as Miller.

“If that road opens up without those measures, I might as well forget going to work in the morning,� Miller said. “If (the measures) don’t go in, it’s going to be a funnel (of traffic) right into Diamond Bar.

“We’re not trying to be unreasonable with Chino Hills,� he added. “I feel for those people. I don’t like to see them with that problem. But I don’t want that problem put in Diamond Bar.�

Walker said he also is trying to be sympathetic to the plight of Diamond Bar residents, but added, “It will be worse for Chino Hills if that road doesn’t open than it will for Diamond Bar if does.�