Comprehensive Study on Traffic Congestion in Urban Los Angeles Suggests Ways to Improve Traffic

For Release

October 2, 2008

The RAND Corporation today released a study that offers a comprehensive look at Los Angeles traffic, debunking common myths about the metropolitan region's traffic patterns and detailing the reasons why congestion is so bad — and why it will get worse in the coming years without significant policy changes.

The report also offers a broad, integrated package of actions that RAND researchers say could improve traffic conditions and enhance transportation alternatives within the next five years, and be sustainable into the future.

“Some of the strategies this report recommends — especially those that would raise the cost of driving — are likely to prove controversial,” said Paul Sorensen, the study's lead author and an operations researcher at RAND, a nonprofit research organization. "But without bold action, congestion across the region will only get worse and cost everyone more — financially, environmentally and through a diminished quality of life."

By many measures, the Los Angeles metropolitan area leads the nation in urban traffic congestion. For example, the metropolitan region ranks number one for total annual hours of delay for all travelers and total annual gallons of wasted fuel for all travelers.

Researchers say the region already has adopted most of the "easy" ways to reduce congestion — those that are effective, affordable and uncontroversial — such as freeway on-ramp meters, traffic signal timing, and ridesharing programs. Complicating matters is the fact that the County of Los Angeles has 88 cities, which makes it difficult to implement strategies that require coordination among different jurisdictions.

RAND researchers compiled their recommendations for improving the region's existing transit and traffic systems after studying successful efforts in cities around the world, including London, Singapore and Stockholm, and many major urban cities in the United States, such as New York and Seattle. A panel of noted local transportation experts served as project advisors.

The RAND study analyzed 28 possible strategies for easing congestion in the urban Los Angeles region, under the categories of: managing demand for peak-hour automotive travel; reducing the cost and/or improving the attractiveness of alternatives to car travel; and making more efficient use of existing roadway capacity.

Major transit infrastructure and other land use related options were not evaluated, only measures that could feasibly be implemented and produce results within five years. The study also focused primarily on passenger travel, not the transport of goods.

Thirteen options were selected as being the best and most effective, based on their individual merits as well as their complementary interactions. Three of the 13 are contingent recommendations — these are strategies that merit further study on how they might be used in Los Angeles. The recommendations are:

  • Install curbside parking meters that charge more during peak business hours for parking in congested commercial and retail districts.
  • Enforce the existing California state law that allows employees to "cash out" the value of their parking spaces. Companies with more than 50 employees who lease parking are supposed to offer their employees the option of cash instead of free parking, but this law is not enforced.
  • Implement local fuel tax levies at the county level to raise transportation funds.
  • Develop a network of high-occupancy/toll lanes on freeways throughout Los Angeles County.
  • Evaluate the potential for implementing tolls on those entering major activity centers, like those that exist in London and Singapore.
  • Expand rapid bus transit with bus-only lanes on arterial streets and express freeway service in the high-occupancy/toll lanes.
  • Offer and aggressively market deeply discounted transit passes to employers, who would purchase passes for all employees, allowing those who commute by transit to ride at reduced cost.
  • Develop an integrated, region-wide network of bicycle pathways.
  • Restrict curb parking on busy arterial streets.
  • Convert selected major surface streets to one-way streets.
  • Prioritize and fund investments in upgraded signal timing and control.
  • Bolster outreach efforts to assist businesses in promoting ridesharing programs, telecommuting and flexible work schedules.
  • Evaluate the costs and benefits of implementing a regional incident management system on the arterial streets to reduce congestion caused by traffic accidents.

The RAND study also outlines how congestion in Los Angeles might be a lot worse if regional planners and officials already hadn't implemented numerous strategies, including some suggested in the report that have been adopted in part or in geographic pockets of urban Los Angeles.

Charging fees for driving and parking during peak travel times, also known as congestion pricing, is a key component of the recommendations. And although such individual recommendations may face initial opposition, many of the complementary strategies work to offset concerns or objections to those measures.

"Congestion pricing is met with resistance when people first hear about the concept," Sorensen said. "Nobody wants to pay more money for something they've previously gotten for free, and many are skeptical that congestion pricing will actually work. And there's a legitimate concern that if it's not properly implemented, it could end up being more of a burden on the region's poor."

But, according to Sorensen, studies of congestion pricing in other cities have shown that the approach is extremely effective in reducing peak-hour traffic congestion and the popularity of the congestion tolls increases as residents become more familiar with how well it works.

Also, drivers from all income groups can and do benefit from the option of paying to avoid congestion delays when they have an important business appointment, a doctor's appointment, or a child to pick up from daycare. Congestion pricing also raises enough revenue to fund significant transit improvements, benefiting existing transit riders and providing better options for current drivers who would like to avoid paying peak-hour congestion tolls.

"Pricing strategies are the only sustainable option for reducing congestion over the long-term, and they will be immediately effective upon implementation," said Martin Wachs, director of the RAND Transportation, Space, and Technology Program, and one of the authors of the report.

It doesn't take a huge reduction in traffic to make a difference: even 2 percent to 3 percent fewer cars on the roads could reduce congestion by 10 percent to 15 percent. But these reductions are usually only temporary, Wachs said. When traffic conditions on a roadway are improved during the peak hours -- such as by adding new roads -- additional travelers will converge on that road from other times of travel, other routes of travel and other modes of travel.

"People notice that there's less traffic on the 405 Freeway during rush hour, and say to themselves, ‘Now I can go back to driving during rush hour,' or ‘Now I don't have to leave by 2 in the afternoon,' or ‘Now I don't have to take the surface streets instead of the freeway,'" Wachs said.

In fact, the only strategies that work over the long term are those that rely on pricing, researchers say. User fees such as road tolls, gas taxes and parking fees raise the cost of driving, providing an ongoing incentive for people to avoid driving during the busiest hours in the most congested areas.

Contrary to the stereotype of Los Angeles as having a long-standing "love affair" with the automobile, per-capita driving in Los Angeles is not excessive in comparison with other large urban areas in the country, although Los Angeles residents do drive a lot compared to residents in other large cities with a similar population density, according to researchers. The region's road network is well-developed and transit service is robust — second only to New York in terms of service miles provided per year.

So why is traffic so bad? The population density of Los Angeles metropolitan region is very high in urbanized areas, and parking is cheap and abundant. Most drivers do not pay the full economic and social costs of driving. Los Angeles also is polycentric: instead of one single, dominant downtown region, it has many sub-centers with high populations or job densities. Though polycentricism can spread traffic out, it also makes it more difficult to provide a fast, effective, and well-connected transit network and reinforces auto-reliant travel patterns, according to researchers.

The research was conducted by RAND's Transportation, Space & Technology program, a part of the RAND Infrastructure, Safety and Environment division. The division's mission is to improve development, operation, use and protection of society's essential built and natural assets; and to enhance the related social assets of safety and security of individuals in transit and in their workplaces and communities.

Other authors of the study are Endy Min, Aaron Kofner, Liisa Ecola, Mark Hanson, Allison Yoh, Thomas Light and Jay Griffin. The study, "Moving Los Angeles: Short-Term Transportation Policy Options for Improving Transportation," is available at

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