Without state and local intervention, San Joaquin Valley cities with high-speed rail stations will become bedroom communities, sending out waves of tech workers on express trains to the Bay Area and Los Angeles, a report released Wednesday by nonprofit think-tank SPUR argues.

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While the Central Valley could potentially serve to supply the cheap housing that has eluded Bay Area-based workers, report author Egon Terplan says that would fail to capitalize on perhaps the single greatest infrastructure investment the state will make this century. Rather than being the tide that lifts all boats, high-speed rail could widen already-stark income disparities between central valley regions and wealthier. more populated coastal neighbors, he said.

If it’s done right, Terplan said those Central Valley cities can reverse years of high unemployment and disinvestment and become incubators for fledgling companies seeking cheaper rents outside the urban poles while still staying only a one- to two-hours’ commute away from either end, he said.

But, it won’t be easy.

State and local officials will have to resist market pressures that for decades have favored single-family homes sprawled across former farm and pasture land. They will also have to find the money to beef up local transit options near the new rail stations if they want to encourage denser development and offer viable transportation alternatived in the auto-dominated region.

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“This is our only chance to really fundamentally change the trajectory of the economy, particularly for these parts of California that have been left out of so much of the economic boom that has been experienced on the coast,” Terplan said. “Getting these details right over the next couple of years (while) this system is still under construction, is really a legacy we want to leave for future generations of California.”

Some progress has already been made. Caltrans is in the process of developing its 2018 state rail plan. That plan will take a comprehensive look at how to integrate high-speed rail with local and regional public transit, with the goal of making each system in the statewide network work more efficiently, said Chad Edison, the deputy secretary of transportation for the California State Transportation Agency, or CalSTA.

But regional transportation is still largely in the hands of local officials, and they do not all see high-speed rail as the panacea to remedy their city’s economic woes. In Bakersfield, officials have serious doubts about whether the rail service will materialize at all, and if it does, if it will perform as promised, said Bakersfield City Manager Alan Tandy. The full $64 billion project is not yet fully funded, and much of its success hinges on the first $20.7 billion “valley to valley” section connecting San Jose to Fresno.

Bakersfield is still working with the California High Speed Rail Authority to implement the city’s preferred alignment through town, Tandy said. If it gets the rail alignment it is seeking, the city would begin making plans for how to reorient development to accommodate and capitalize on potential new growth the station may bring, he said.

“Nothing is predictive that they will complete the project,” Tandy said. “Our actions are contingent on the possibility they may.”

Assuming the railroad is completed, Tandy said it will likely be inevitable that Angelenos will start seeking homes in Bakersfield, which historically hasn’t exported workers. At the same time, city officials are planning for a denser downtown that preserves open space, improves transportation corridors, adds access to the river, and improves biking and pedestrian facilities.

On the other end of the spectrum, city officials in Fresno are fully embracing high-speed rail, perhaps because construction has already started in their city, and have already begun applying for state funds in anticipation of expected growth. The city, which runs its own public transit system, has started construction on two bus rapid transit routes to shuttle rail passengers to the northern and eastern parts of the city, said Planning Director Dan Zack. And, they’ve already adopted a station-area master plan that allows for buildings up to 15 stories tall.

Fresno has secured $70 million in state funds to encourage dense development downtown that supports walking, bicycling and public transit, he said. The money is needed to improve infrastructure that will complement private development, which despite the promises of growth related to high-speed rail, is not as strong as the city would like, said Fresno Mayor Lee Brand. But, that hasn’t deterred his optimism about the potential prosperity high-speed rail could bring.

“The promise of high-speed rail is that it extends Fresno to the rest of the state in a way we’ve never seen done before,” he said. “We don’t just want to be the bedroom community, we want commerce to spring up in Fresno.”

For that to happen, Terplan said cities need more than state funding to fill investment gaps. Redevelopment authorities, the one tool at city officials’ fingertips, have been dissolved statewide, though the report argues development corporations should be reinstated for a limited time to focus new growth in cities that have high-speed rail stations.

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“It’s still hard to get as much development as many would like, and there continues to be pressure to convert farmland,” Terplan said. “We are seeing some small successes, but what we do not yet have is a strong enough state framework and set of policies to really give those cities the tools to make their downtowns, and high-speed rail, thrive.”