HARRISBURG — Competing Pennsylvania transportation funding proposals took shape Friday, days before the state House of Representatives appeared likely to vote on whether to raise billions of dollars to improve the roads, bridges and mass transit systems.

Top legislative aides said a House vote could come as early as Monday, although it was unclear which proposal the House might favor.

“We’re feeling pretty good about where we are,” said Dave Thomas, who is closely involved in the negotiations as an aide to House Speaker Sam Smith, R-Jefferson. “The speaker’s been talking to members for the last couple of days. I’ve been hearing some positive signs from the Democratic caucus about their level of support. I think we’re in as good a shape as we can possibly be right now.”

Republican Gov. Tom Corbett has made transportation funding his top priority this fall, but House leaders have struggled for months to respond to the Senate’s June 5 passage of a $2.5 billion plan.

The leading House Republican proposal, sponsored by the House Transportation Committee chairman, would increase gas taxes and a host of motorist fees to eventually generate at least $2.3 billion a year.

Democrats have introduced a nearly identical plan, but they would eliminate the GOP’s proposal to exempt more local transportation projects from state wage requirements.

House Democratic spokesman Bill Patton said the leaders reached a consensus on the transportation aspects of the plan but not on the wage changes.

A second Republican proposal, championed by Majority Leader Mike Turzai of Allegheny County, generates $1 billion a year, including $380 million for mass transit.

Whatever passes the House would still require approval from the Senate to make it onto Corbett’s desk.

The leading Republican proposal and the Democratic plan would eliminate the state’s 12-cents-a-gallon flat tax on gasoline but replace that revenue by increasing the wholesale tax on gasoline. The wholesale tax, known as the oil company franchise tax, would generate new revenues by being applied to the full price of gas. The cost would likely be borne entirely or mostly by consumers.

Mass transit agencies would get nearly $500 million more a year. The bill would phase in the tax increases over five years, and people involved in writing it say precise figures are difficult to determine because they are pegged to the future price of gas.