Public support for increasing transportation taxes can be strongly increased by linking revenue raisers to environmental benefits and by spreading an increase out over several years, according to a national survey released last Friday by the Mineta Transportation Institute at San Jose State University in California.

Researchers found that support was 19 percentage points higher for a proposed 10-cent-per-gallon gas-tax increase dedicated to transportation projects that reduce global warming compared to raising the tax without any reference to how the revenue would be spent. Spreading out a dime-per-gallon increase over five years (2 cents per year) increased support by 16 percentage points versus implementing the full increase in the first year.

The report was issued at a forum hosted by the Commonwealth Club in San Francisco: "Funding the Transportation System of the Future: What's Possible in the Current Anti-Tax Climate." Panelists included former U.S. Transportation Secretary Norman Mineta; John Horsley, executive director of the American Association of State Highway and Transportation Officials; William Millar, president of the American Public Transportation Association; California state Sen. Alan Lowenthal; and report author Asha Agrawal.

Researchers randomly surveyed 1,545 American adults by telephone between April 27 and May 22 about whether they would support eight options for increasing transportation taxes. Three base cases were tested: raising the federal gasoline tax from 18.4 to 28.4 cents per gallon, implementing a driving tax of 1 cent per mile, and initiating a half-cent national sales tax. Respondents were also asked about five variations on a gas or mileage tax.

None of the eight options received majority support from those polled. The half-cent national sales tax for transportation received the greatest support at 43%, followed closely by a dime-per-gallon gas-tax hike with revenue dedicated to transportation projects to reduce global warming (42%) and a dime-per-gallon gas-tax hike spread out over five years (39%).

During his presentation at last Friday's forum, Horsley noted that 20 states have announced they intend to cut spending on transportation this year. Only four states (Minnesota, Oregon, Rhode Island, and Vermont) and the District of Columbia have increased their gasoline taxes since 2008. (Kansas recently enacted a sales-tax increase to support transportation spending.)

The federal Highway Trust Fund, meanwhile, has been propped up by the transfer of $8 billion of General Fund revenue in 2008, $7 billion in 2009, and $19.5 billion this year. The federal gas tax has not been raised since 1993.

"Absent congressional action to provide additional revenue, when this General Fund support runs out in Fall 2011, the federal highway program will have to be cut from $42 billion to $21 billion and the transit program cut from around $11 billion to $7.5 billion," said Horsley, who is a member of the Mineta Transportation Institute's Board of Trustees. "Eventually we are convinced that fiscal sanity will return and that legislators and voters will both agree that investing in transportation infrastructure is vital to the economy and that we can't borrow our way into the future. For now, few are being convinced by that argument."

The 64-page report, "What Do Americans Think About Federal Transportation Tax Options? Results from a National Survey," is available at tinyurl.com/MTI0625.