Officials from the 10-county region have adopted a federally mandated Transportation Improvement Program that will guide road, bridge and transit improvements for the 2009-12 period.

A draft of the $3.7 billion transportation blueprint was approved this week by the Southwestern Pennsylvania Commission, which also acts as the Metropolitan Planning Organization for Allegheny, Westmoreland, Washington, Indiana, Armstrong, Greene, Fayette, Beaver, Lawrence and Butler counties.

The plan includes starting the long-sought widening of Route 28 between the North Side and Millvale, rehabilitating the Liberty Tunnels and widening almost a mile of Lincoln Way/Route 30 through White Oak.

The draft TIP, traditionally approved in final form with few changes, establishes priorities and identifies funding for those three and 677 other transportation projects in various development stages: design, right-of-way acquisition, utility relocation and, finally, construction.

The TIP is updated every two years and occasionally amended because of emergencies or when projects advance faster than anticipated. But unless a project appears on the list, it isn't eligible for federal funding.

The final 2009-12 program must be approved by the commission and the state by Oct. 1.

Bridges represent a significant difference in the new TIP, inasmuch as they make up 380 of the total 680 projects. In addition, the amount of money to be invested in them has increased by almost $600 million, nearly double the amount in the TIP that's expiring.

Projects range from preventive maintenance on the sister Sixth, Seventh and Ninth street bridges over the Allegheny River to preparing the final design for a new Greenfield Avenue Bridge over the Parkway East.

The latter is the landmark concrete arch structure enveloped in nets and with a deck-type structure built over the parkway because of deterioration. The devices catch small pieces of concrete and falling debris before it hits vehicles on the busy highway.

A total of $12.7 million is listed to rehabilitate the Liberty Tunnels; nearly $70 million to start widening Route 28/East Ohio Street, including relocating the adjacent railroad tracks; $10.4 million for the Lincoln Highway widening; and $12 million for a new Tri-Boro Expressway bridge over Turtle Creek in North Versailles.

Other projects on the TIP include six ramps/bridges on Route 65 around Marshall Avenue in the city; the rest of Route 22 reconstruction in Westmoreland and Indiana counties; the Wayne Street Viaduct in Butler; and rehabilitation of the Rankin, West Kittanning, Masontown, Freeport, Donora-Monessen and Veterans/Beaver County bridges.

TIP documents and a list of all projects can be found at the commission's Web site, www.spcregion.org and click on "transportation."