For the better part of a year, plans for a high-speed rail line through Fresno have included miles of elevated tracks soaring 60 feet above the central city streetscape.

Now, in a surprise to many observers, engineers are evaluating where tracks can be built at ground level instead as a way to save money.

The about-face by the California High-Speed Rail Authority comes amid rising concerns over the cost of the train system and fears about the noise and aesthetics of overhead tracks in communities. The new strategy, called "value engineering," was publicly acknowledged this month by the rail authority's CEO, Roelof van Ark.

The authority hopes to begin construction in late 2012 on its first 120-mile section of high-speed train tracks between Fresno and Bakersfield. It would be the first stretch of what is ultimately planned as an 800-mile system, connecting the state's major urban centers with trains traveling up to 220 mph.

A year ago, engineers had ruled out several at-grade route options through Fresno as being impractical or too disruptive to traffic and nearby neighborhoods. More streets would have to be closed or relocated, and construction would be complicated by having to build new over- and undercrossings for major streets, and rebuild overcrossings for Highways 41 and 180.

Fresno Mayor Ashley Swearengin is glad to see that ground-level tracks are back on the table.

"We're positive about the approach [the authority] is taking," said Swearengin, who has been supportive of high-speed rail -- and the economic spark she says it could provide for the city. "The city is strong in its push for design alternatives that work for the city and its residents."

What doesn't work for Fresno, she added, is a continuous six- to eight-mile stretch of elevated tracks above central and downtown Fresno.

"From very early on, I had deep concerns about elevated tracks through our city," Swearengin said last week.

Such structures, she said, would create "a visual dividing wall in our community," in much the same way that Highway 99 created a social and economic divide when it was built through the city decades ago.

To elevate or not?

Three possible routes through Fresno remain on the drawing board and are going through detailed state and federal reviews of potential effects on the environment, traffic, public safety, cost and disruption to the community.

All three lines generally run along the Union Pacific Railroad tracks between the San Joaquin River and downtown. South of downtown, the lines curve south to follow the Burlington Northern Santa Fe Railway tracks.

Since last spring, all three options have depicted tracks gradually rising near Clinton Avenue and continuing southward on a raised guideway to an elevated downtown station. South of downtown, the tracks would gradually return to ground level near Central Avenue.

One line runs along the west edge of the Union Pacific right-of-way from Clinton Avenue all the way through downtown. Another starts on the west side of the UP tracks and crosses overhead to the east side of the tracks near McKinley Avenue. It remains on the east side through downtown before curving southward out of town.

Then there's a hybrid route that starts on the west side of the UP tracks, crosses to the east near Olive Avenue to avoid Roeding Park, and weaves back to the west near Highway 180 to continue through downtown.

"What we're looking at now on those three elevated options is where we can make them at-grade," said Rachel Wall, press secretary for the high-speed rail authority. "We're looking at design solutions to reduce the cost without diminishing performance."