WASHINGTON - Congress' three-year struggle to adopt a new six-year highway and public transportation law is moving to a House-Senate conference committee now that both chambers have passed their own versions of the massive legislation.

The House adopted a $280 billion bill late last month before adjourning for two weeks. The Senate version, which was adopted in February, would allocate $318 billion for federal highway and transit programs.

President Bush has threatened to veto any highway bill that proposes spending of more than $256 billion. However, both the Senate and the House approved their bills by lopsided margins. In fact, the approval votes were wide enough to sustain a presidential veto.

The conference committee will seek to iron out differences between the House and Senate bills. The committee's work will be followed closely by the motorcoach industry, which is particularly interested in the sections covering federal charter bus rules.

Both versions of the highway bill provide for penalties if a transit system violates the charter bus rules. However, the House version would, for the first time, give the secretary of the U.S. Department of Transportation flexibility in penalizing a transit system that routinely violates the rules.

The motorcoach industry lobby likes the idea of the USDOT being able to withhold a little or a lot of money, depending on the extent of the violation by the transit agency.

Industry lobbyists, with strong grass-roots support from motorcoach operators across the U.S., were able to convince House members to reject draconian changes to the federal charter services rules approved by the Senate.

The Senate voted to allow transit systems to provide incidental charter service to government agencies and social service organizations "with limited resources." It also approved a process that would allow public transit agencies to act as brokers between private operators and their customers.

Report language attached to the House bill directs the Federal Transit Administration to undertake a rulemaking on ways to improve the enforcement and administration of the federal charter rules. Congress also wants the FTA to address the issue of whether transit systems - in limited situations - should be allowed to provide charter service to local governments and nonprofits that would not otherwise be serviced in a cost-effective manner by private operators.

Many industry lobbyists and others who have been tracking Congress' work on the highway bill differ over whether it's smart to let the FTA take a shot at writing new rules covering enforcement of the charter rules.

There's fear the FTA will mess up the process and gut the current rules by caving in to pressure from public transit agencies.

Jim Seal, a consultant to the California Bus Association and an expert on the machinations of the FTA and the federal charter rules, is less fearful than some.

He says the rulemaking process "would allow us to involve our Congressional allies on the small business aspects of charter service to make sure the FTA does not capitulate to the public sector which it would do without broad involvement from all of us and our supporters."

Seal says the language in the House report on its highway bill "can certainly be interpreted as a compromise to address issues from both sides. I think we can make a case that the House has struck a balance in that all sides have a chance to make their case," Seal notes.

"At the end of the day, (the American Public Transportation Association's) concerns have been addressed. Conversely, we can achieve the goal of giving FTA flexibility to start to actually penalize operators for repeated violations if the House language prevails without the exceptions and brokering provisions.

"We can control our destiny and improve our lot so long as private operators and associations are involved in the process. . . . The charter statute will be amended and rulemaking is inevitable and that can be a huge gain for the private sector if we disclose how all needs are being cost-effectively met. We have a compelling case to make, just like the last time under the charter bus demonstration project," Seal adds.

"Of course, we now have the conference committee process to go through which will require the same dedicated effort that we all put into shaping the House version."

Other aspects of the two highway bills are important to the motorcoach industry.

For example, both bills would extend the axle-weight exemptions for over-the-road and transit buses. While the current law contains an axle-weight exemption, whether buses have to pull into scales or not is left to the discretion of the states. The new Senate bill contains a provision that excludes both transit buses and motorcoaches from even having to stop at scales on federal highways.

The House bill reauthorizes the over-the-road bus accessibility program, which awards grants to private bus operators to help defray the cost of installing wheelchair lifts. However, the funding ratio would be changed.

The fight over the size of the new highway and transit bill could be contentious, considering the president's veto threat.

Bush has not issued a veto during the nearly 3.5 years of his presidency, but he is under considerable pressure from fiscal conservatives to slow congressional spending and the highway bill is an obvious target.

All versions of the highway legislation, including the White House bill, contain big increases over the 1998-2003 law. It was funded at $218 billion.

The breakdown of the House spending shows $222 billion going to highway programs, $51.5 billion for public transit, and $6 billion for safety and research programs.

It's expected that motorcoach industry trade associations will be seeking members' involvement in the conference committee debate over a combined highway bill.