Earlier this year, a bipartisan transportation bill passed the Senate with the overwhelming support of some of the most liberal and conservative voices in Congress. That bill takes important steps to reduce our dependence on oil and move our transportation system into the 21st century.

Most important, it will save 2.9 million American jobs while improving our crumbling transportation infrastructure over the next two years.

Sadly, House Speaker John Boehner and House Republicans looked at a good bill and saw the chance to help their dirty-energy benefactors. Boehner has gone out of his way to imperil both the future of our transportation system and millions of American jobs by tying them to risky projects benefiting nobody but the world's largest oil and coal corporations.

These big-polluter sweeteners include approval of the previously rejected Keystone XL pipeline, elimination of proposed protections from cancer-causing coal ash and an evisceration of the nation's 42-year-old environmental-review process.

At a time when our transportation system is in dire need of job-creating repairs and upgrades, the Senate version of the bill, while not perfect, has America's transportation priorities in order.

This bipartisan initiative would get Americans back to work; encourage cleaner, safe alternative modes of transport; and secure funding for highway expansion to reduce congestion while keeping our air clean. The 90-day extension of previous transportation legislation expires on June 30.

We need not look further than our morning commute to understand why a new transportation bill must be passed. Ensuring that these projects move forward not only provides certainty for drivers on the road and users of public transport, but also safeguards the jobs of construction workers, train operators and other hardworking Americans.

In Boehner's world, though, a vote to save nearly three million jobs is also a vote to increase risk to our water, air and health. The House extension bill would slash safeguards against toxic coal ash, a move that would be disastrous for our families and communities.

In fact, the GOP's bill treats coal ash, a proven carcinogen, as less threatening than common household garbage - even though its dangers have been clear for years.

Boehner's vision for America's transportation future is especially dangerous for Florida, where communities like Orlando and Tampa Bay struggle with air quality and traffic-congestion problems. Orlando and Tampa also have the dubious distinction of ranking first and second, respectively, as the nation's most dangerous places for anyone daring to walk.

Florida's economy needs the comprehensive array of transportation choices that most other Americans now enjoy. The absence of those choices prevents the state from competing with U.S. cities that obtained federal support to develop their transportation infrastructure.

Yet, Boehner's bill would reduce or eliminate funding for expanded bus service, light-rail networks and safer paths for bicycles and pedestrians. To add insult to injury, it would gut our nation's environmental-review process, which ensures that the public has input on transportation projects that significantly impact local communities.

On top of that, the House's bill also includes a rubberstamp for the Keystone XL tar sands pipeline - a move that could easily sink the bill and the millions of jobs it will bring. There's a simple reason why Keystone XL has already been rejected by the Senate and declared dead-on-arrival by the president. It's just too risky.

TransCanada's pipeline would endanger vital water sources of millions of Americans. All of this would simply allow the Canadian oil industry to ship its dirty energy around the world and, as study after study shows, raise gas prices at home. The U.S. gets all the risk and little of the reward.

But soon, Sen. Bill Nelson, as a conference committee member hammering out the details on a final transportation bill, will make the choice between a clean, bipartisan bill that brings our transportation system into the 21st century or a bill that contains dangerous add-ons and divisive pet projects. We need Nelson to make the right choice now more than ever.

The solution is simple: Ignore the poison pills, pass a clean transportation bill and save 2.9 million American jobs.

Frank Jackalone is Florida staff director of the Sierra Club.

Copyright © 2012, Orlando Sentinel