Building the roads and transportation infrastructure needed to accommodate Southern California's surging population could cost more than $100 billion, according to planners, leaving the region's taxpayers with a tough choice ahead.
Local transportation agencies said the Southland's freeways and mass transit need drastic changes to accommodate what state officials project as a 60% increase in the region's population by 2050.
That would probably include adding upper decks to some Los Angeles County freeways, new rail lines and building freeways or toll roads in places like the Antelope Valley, Orange County and Riverside County.
"We are thinking here of a big system, equivalent to the interstate system," said Hasan Ikhrata, director of planning and policy for the Southern California Assn. of Governments, referring to the freeway building boom of the 1950s and 1960s that revolutionized American auto traffic.
The population forecast, released Monday by the state Department of Finance, predicted that California's population would swell to nearly 60 million by midcentury. Southern California's population would reach 31.6 million by 2050, up from 19.5 million in 2000.
Some demographers believe that the state will only reach those numbers if it provides adequate public infrastructure. Others worry that the growth will come even without more roads, making congestion worse.
"The Westsiders won't cross the 405. The west San Gabriel Valley people will stay in their little pocket," said Dowell Myers, USC professor of urban planning and demography. "We're going to live and work more in villages."
Politicians and transportation planners have been grappling for decades with how to make road improvements keep up with the rising population -- and many admit that they have largely failed. The percentage of highways in the state deemed congested rose from 32% to 43% from 1992 to 2002, according to a California Department of Transportation study, which defines congestion as rush-hour traffic that moves at 35 mph or less.
In November, California voters approved a $19.9-billion transportation bond measure, hailed as a major milestone.
But the planning studies put the bill for keeping congestion in check at $140 billion in the next 30 years for six Southern California counties.
Paying for the improvements will be difficult. Many counties -- including Los Angeles, Orange, San Bernardino and Riverside -- already have a sales tax for transportation projects.
Many say boosting the gas tax would be the most logical way to collect more revenue. But it is politically unpopular with prices at the pump so high. California and the federal government each impose a gasoline tax of 18 cents a gallon, a rate that has not changed since the early 1990s despite a sharp rise in gas prices. Because the tax has not been adjusted for inflation, California has struggled merely to maintain its existing roads.
And without more roads, "we will be in a serious congestion crisis from the Oregon border to Mexico," said Eric Haley, executive director of the Riverside County Transportation Commission.
One reason the potential fixes cost so much is that there is so much less raw land than there was in the 1950s. As a result, officials must go to great lengths to engineer new roadways:
* Several of the routes considered most crucial by traffic planners require tunneling under neighborhoods or mountains. These include extending the 710 Freeway through South Pasadena, creating a link under the Santa Ana Mountains from Riverside to Orange counties and boring a tunnel from the Los Angeles Basin through the San Gabriel Mountains into the Antelope Valley.
* Los Angeles County has the most severe land crunch, so officials say the only way to significantly improve capacity is to double-deck freeways. A portion of the 110 Freeway in South L.A. is a model, allowing carpools and buses in special elevated lanes.
* Toll roads are gaining new attention because officials could use future revenues to borrow money to build the highways. Officials have talked about an expressway connecting the fast-growing high desert regions of Los Angeles and San Bernardino counties, and construction is almost completed on a 10-mile toll road east of San Diego.
* The surge in Riverside County's population -- expected to leapfrog Orange and San Diego counties and become the No. 2 county in the state -- also means the many assumptions about transportation need to be revised. Ikhrata said north-south roads that connect far-flung suburbs in the Inland Empire are needed, rather than the traditional east-west roads that connect those suburbs to Los Angeles.
Besides moving the growing number of commuters to work, government planners predict a 400% increase in cargo movement over the next 30 years, further taxing the freeway system and probably requiring truck-only toll lanes on heavily traveled routes such as the 710, 60, 5, 10 and 15 freeways.