Harried south Sacramento County commuters who each day deal with congested freeways must now wait longer for a promised rail rescue.

The opening date for a light-rail connection between south Sacramento and the northern reaches of Elk Grove has been pushed back a year – to 2012. And the price tag has jumped 23 percent to $270 million, officials said.

"We're a little shocked ourselves," Regional Transit official Diane Nakano said.

The delay and price jump stem from a recent "risk analysis" conducted by the Federal Transit Administration, which is expected to pay half the cost of starting up service over a 4.3-mile stretch of track.

Government analysts concluded the planned Meadowview Road to Cosumnes River College line is worth doing but will take hard work to pull off.

The rail line will squeeze through tight quarters along freight tracks and existing neighborhoods, over a creek and levees, across a floodplain, through endangered-species habitat, and across several major streets.

RT officials say those difficulties corroborate what they've learned: It's increasingly difficult to finance and build transit in a busy urban area.

Yet south county leaders and regional transportation planners say they see unprecedented interest among commuters for alternatives to cars, crowded freeways and high gas prices.

They predict the rail line will become an important pressure release valve for congested Interstate 5 and Highway 99.

RT officials say they are trying to arrange local and state funds to pay their half of the cost, and are working to clear a long list of hurdles before a hoped-for start of construction next year.

Nakano, RT's engineer for the project, said the agency will look for ways to speed the building process.

"But the devil's in the details," she said

The transit agency has yet to negotiate with the Union Pacific Railroad over use of part of the freight company's rail right of way.

It also must come to terms with Pacific Gas and Electric Co. over moving an underground gas pipe so it isn't corroded by stray electrical currents.

RT officials await word from regulators – with fingers crossed – on what kind of flood control and levee work they must do along the way.

They already know they will be prohibited from working in certain areas during the wet season so they don't disturb habitat for giant garter snakes, an endangered species.

The agency also expects it will have to muffle train noise in residential areas and negotiate to acquire land for stations.

Although operating costs for rail are cheaper than buses, construction costs – an estimated $63 million a mile for the new line – are straining an agency with limited funds.

It's caused some transit riders to advocate for more buses. Other commuters clamor for more and better roads.

But no form of urban transportation – train track, street or highway – is cheap these days, planners say.

Already in the south area, state Transportation Department officials expect to spend more than $200 million to build just one carpool lane per direction on I-5 from Elk Grove to near downtown Sacramento.

On nearby Highway 99, freeway expansion is simply a no-go because it would require tearing out homes and businesses, officials say.

Regional transportation planner Mike McKeever, head of the Sacramento Area Council of Governments, said the planned rail extension has both a particular benefit and a broader appeal.

"Some of the strongest ridership comes from college students, faculty and staff," he said.

"Rail of any kind – trams, streetcars, light rail – is a critical part of the regional framework. We need rail if we are going to have a viable transportation flow."

Call The Bee's Tony Bizjak, (916) 321-1059.