SMCLC has been advocating that our city must have a newer, more accurate way of counting and determining traffic impacts. The LA Times article below, includes, among other things, an admission by the LA city planning director that there needs to be a new, better way to count traffic for projects because the model being used (same as Santa Monica) is "seriously underestimating the cumulative impact of the growth in the community".

July 31, 2007
Los Angeles Times

link: LA Times

Local traffic count method sought
Two on the council want L.A. planners to find more accurate ways to predict the effect of a raft of new building projects on roadways.

By Sharon Bernstein, Times Staff Writer

With road congestion worsening and development booming, L.A.'s top planner and other city officials said Monday that Los Angeles may be underestimating the traffic generated by all the new projects and urged major changes in how the estimates are made.

The effort to more accurately count traffic comes amid growing concerns about how the building boom underway downtown and in the Westside, San Fernando Valley and other parts the city is affecting already jammed streets and freeways.

The city Planning Department uses a national model that takes into account traffic patterns in several cities, including New York, San Francisco and Miami, to predict how much traffic a project would generate. Developers are then required to pay for left-turn signals, freeway offramps and other roadway improvements meant to lessen congestion caused by people going to and from new structures.

But Planning Director Gail Goldberg on Monday said the national standards might not work in Los Angeles, which has an unusual amount of urban sprawl and a limited mass transit system.

Rather than rely on information from cities with better transportation systems or less sprawl, Los Angeles should develop its own system of estimating traffic based on the way people here drive and where they live, she said.

"We are seriously underestimating the cumulative impact of the growth in a community," Goldberg said.

Without changing the way we estimate traffic — and integrating that information into a citywide system of community plans — neighborhoods could become more and more congested, despite the city's best efforts to keep traffic flowing, Goldberg said.

Revised traffic counts could create obstacles for developers if shopping centers, condo complexes and other projects were judged to generate more traffic than the national model indicates. And if those projects were found to have a greater impact on traffic, the cost of such improvements could soar.

If the city chooses to develop a sophisticated model, the effort would require extensive research. Planners would have to count cars on streets and freeways throughout the city and develop mathematical models to consider the number of car trips generated by people going to and from shopping centers, homes and businesses. The model would also have to consider the effect of people who drive into a neighborhood from other communities or cities.

"The traffic counts need to reflect the neighborhoods where development occurs," said Councilwoman Wendy Greuel, who represents the Valley. She and Councilman Bill Rosendahl, who represents the Westside, will ask the Planning Department at today's council meeting to propose new ways of estimating the impact of development on traffic.

Properly estimating traffic has become an issue as several large projects are coming on line around the city. Included are high-rise condominium towers planned for Century City, mixed-use developments along Hollywood Boulevard and a proposed expansion of the Sherman Oaks Fashion Square mall.

Local residents have complained that the city is underestimating the traffic effects of the developments. But supporters have said that because the projects include a mixture of residential and commercial uses they would generate less traffic because the residents can walk to work or shop there.

Ellen Vukovich, a board member of the Sherman Oaks Homeowners Assn. who is concerned about traffic and overdevelopment, welcomed a new way to predict traffic. But she said it could be years before the model is complete — and by then the large projects in the pipeline would be built.

"It sounds really good, but in the meanwhile, what are we supposed to do?" Vukovich said. She suggested that the city put in place moratoriums on growth until the new data is available.

Robert Scott, a former president of the Los Angeles Planning Commission who also heads a Valley business association, said he supported the idea of getting better data, but was concerned about the city's motivation.

"It's always good to be more factual, but if the purpose is to stifle economic development, that would be a mistake," Scott said. "We don't need to make it tougher for people to get through the process."

The move to improve the city's traffic data is part of a broader effort by Greuel and others to consider the cumulative effects of development on communities when deciding whether to allow a project to go forward.

Earlier this year, she asked the Planning Department to estimate the effects of development on a crowded portion of Burbank Boulevard. New local traffic data, she said, could be incorporated into community plans the city is developing for its neighborhoods, so that the overall impact of development could be better understood.

Gloria Jeff, director of the Los Angeles Department of Transportation, said it was not yet known whether local data would show that traffic is higher or lower around new developments than previously believed.

But, she said, having better information would mean that residents would feel more confident that the city was acting responsibly to try to curb congestion.

"Los Angeles-specific numbers would give confidence to communities that their unique needs, wants and desires are being considered," Jeff said.

Genevieve Giuliano, director of the National Center for Metropolitan Transportation Research and a professor at USC, said the city should hesitate before discarding the national model, which was generated by the Institute of Transportation Engineers and includes detailed information about a wide variety of developments and urban environments.

"Unless you are doing something very unusual that's not covered by the formula, it wouldn't be worthwhile to do your own survey," Giuliano said.

Moreover, it's quite possible that once the data is in, the results may be quite different from what city officials expect.

Donald Shoup, a UCLA professor who is an expert on development and transportation, said he thinks the new numbers will show that Los Angeles is overestimating the amount of traffic caused by new developments, not underestimating it.

That's because the national data includes many suburban locations and doesn't take into account public transportation that is available in Los Angeles, Shoup said.

Moreover, real data from the city's most congested areas could show that people are actually driving less, simply because it's so unpleasant to get in their cars, he said.

"A new condominium complex in Century City will not generate as much traffic as one in Orange County, because the traffic is so bad in Century City that people will want to stay close to home," he said.

"People can walk to the Century City shopping center, they can walk to work, walk to restaurants and theaters."

Still, Shoup said he welcomed the proposed change. "Either way, we'll find out what the difference is," he said. "I think it's a good idea."


SMCLC has been advocating for a new traffic impact methodology for some time. Some related items:

SMCLC Seeks to pursue CalTans grant for new traffic count system
... read

Santa Monica resident and SMCLC adviser, Laurel Roennau, has studied traffic impacts for over 20 years. She has kindly provided her report to the SM Task Force on the Environment for us to publish. Her analysis clearly states what is wrong with how Santa Monica measures traffic today and how traffic should be measured to determine true traffic impacts.

download MSWord document

SMCLC Urges Funding of Better Traffic Impact Methodology...more

2/4/06  SMCLC submits a proposal for the City to fund a new traffic impact methodology study with 8% of the City's surplus budget funds... more