Environmentalists scored a victory in Pennsylvania last month after the state agreed to back off plans for a controversial four-lane freeway bypass.

Road warriors in Utah say the win bolsters an argument against the Legacy Parkway because Pennsylvania officials decided to build a smaller, cheaper alternative — one that's similar to a proposed alternative to Legacy.

"What we're excited about here is the precedence," said Marc Heileson, regional representative for the Sierra Club. "This is a case very similar to ours where they (the state) had proposed this freeway bypass. It was hugely expensive, and it was damaging to the environment."

Since December, Heileson and other Legacy foes have been working on the "Citizens' Smart Growth Alternative," which calls for Redwood Road to be extended in Davis County in addition to construction of commuter rail, bus rapid transit and light rail.

It's an environmentally sound plan, would save $300 million and presents a viable alternative to I-15, said Heileson.

He said the victory in Pennsylvania "proves it."

"It shows that these (alternatives) do carry travel demand and are better than interstates that just spread rapid sprawl," he said.

Lucy Gibson, a transportation engineer with Vermont-based Smart Mobility Inc., has been working with Heileson and other opponents to develop the alternative plan to Legacy.

Her firm also worked on an alternative to the Pennsylvania road — parts of which were adopted by the state.

Based on that experience, what Legacy foes are proposing in Utah is very similar to the Pennsylvania project, she said.

The political attitude is also similar.

"The whole planning history of our state departments of transportation has been to focus on highways, but there are a lot of different ways to address transportation needs," Gibson said.

Instead of focusing on roads — and only roads — state transportation departments need to look at "smart growth" alternatives, she said. She said transit deserves a critical look in addition to managed-lane studies and toll roads.

Officials with the Utah Department of Transportation say they have studied the alternatives and embrace the concepts. The Legislature recently approved a resolution encouraging UDOT to begin managed-lane studies.

But how money is spent and where roads are built depends on public input, said UDOT director John Njord.