The world's biggest bridge conference expects the biggest turnout in its 25-year history next week in Pittsburgh, the "City of Bridges."

Up to 1,500 academics, engineers, consultants, researchers, vendors and various officials from North America, Europe and Asia have forced the sponsor, the Engineering Society of Western Pennsylvania, to move the International Bridge Conference from the Hilton Pittsburgh to a bigger venue, the David L. Lawrence Convention Center.

In addition, the number of exhibitors for the accompanying trade show has grown by 25 percent, to more than 150, IBC Manager Ryan Bock said.

Most conference attendees will arrive tomorrow for a program that gets under way at 8:30 a.m. Monday, when Pittsburgh Mayor Luke Ravenstahl will welcome them to the keynote session. It will feature the highest-ranking federal official ever to attend the IBC, U.S. Deputy Secretary of Transportation Thomas J. Barrett.

Mr. Barrett is Department of Transportation's chief operating officer responsible for day-to-day management of its $61.1 billion budget and approximately 60,000 employees.

He'll be followed by Peter Ruane, president and chief executive officer of the American Road & Transportation Builders Association, a federation of public and private transportation construction interests with 5,000 members.

Mr. Bock said the conference timing "couldn't be more appropriate" given the growing number of structurally deficient bridges on the state and national levels, last year's collapse of the I-35W bridge in Minneapolis and the upcoming expiration of the federal transportation funding bill best known by its acronym, SAFETEA-LU.

In January, a 12-member National Surface Transportation Policy and Revenue Study Commission recommended successor legislation when SAFETEA-LU expires next year, including increasing the federal gas tax by 5 to 8 cents a gallon for each of the next five years and imposing a "federal ticket tax" as a new user fee on public transit and passenger train riders.

The Federal Highway Administration is the featured agency at this year's conference.

Besides general sessions, the three-day IBC will offer dozens of workshops, technical sessions, training opportunities, field trips and panel discussions.

A "bus bridge tour" will take a limited number of attendees to South Oakland, where the Pennsylvania Department of Transportation is building a Boulevard of the Allies bridge as part of a new "gateway" to the city's institution district, and to Harmar, where the Pennsylvania Turnpike Commission is building a segmental bridge over the Allegheny River. The tour will finish with a Mon Incline ride to the top of Mount Washington, a vantage point overlooking dozens of bridges.

An associated luncheon will be held Monday at the Westin Convention Center hotel to present special awards to individuals and for bridge projects of distinction, including a unique pedestrian crossing of the Rhine River between Huningue, France, and Weil am Rhein, Germany, whose mayor, Wolfgang Dietz, is coming to Pittsburgh to accept the medal.