HARRISBURG — State officials plan to spend more than $1 billion on improvements to Interstate 80 over the next few years under a plan to convert the 311-mile highway to a toll road.

The improvements would focus on repairing bridges, adding climbing lanes for trucks, upgrading pavement and extending access ramps to the interstate, officials said.

"We are going to issue bonds over the next five years for about $1.1 billion to put into I-80," said Joseph Brimmeier, chief executive officer of the Pennsylvania Turnpike Commission. "If they (motorists) are going to pay a toll, you've got to have a first-class road."

Last month, the state Legislature approved a plan to add tolls to raise money for road and bridge repairs across Pennsylvania, and also provide funding for cash-strapped mass-transit systems. The turnpike commission this month formally asked the Federal Highway Administration to approve the plan; Interstate 80 was built in the 1950s and 1960s with federal funds.

The planned I-80 improvements are authorized under the new state transportation funding law, which was passed after heated debate between Gov. Ed Rendell's administration, state lawmakers and two western Pennsylvania congressmen.

U.S. Reps. Phil English, R-Erie, and John Peterson, R-Venango, have urged federal authorities to reject the toll plan, arguing that tolls would hurt the economies of towns along the east-west interstate.

The commission is studying traffic volume along I-80, and plans to have engineering firms suggest design and structural changes, Brimmeier said. The panel has yet to identify any specific improvements it intends to make, although state lawmakers have some suggestions.