The Pew Charitable Trusts

After Arizona officials quietly informed the federal government that they were thinking of imposing tolls on an interstate highway in the northwest corner of their state, Utah Governor Gary Herbert lashed out at his southern neighbors.

"I strongly oppose any plans to levy tolls on Arizona's portion of (Interstate) 15 or on any portion of I-15," Herbert said in a statement last week. A few hours later, Herbert renewed his criticism at a press conference. According to the (Salt Lake City) Deseret News , the Utah governor said Arizona's proposal was "a reflection of Arizona just trying to find dollars wherever they can because their budget is so upside-down."

Generally, states cannot charge tolls on previously toll-free interstate stretches built with federal money. There is, however, one exception to the rule. In 1998, Congress created a pilot program under which up to three states can start collecting tolls on existing interstates to fund improvements on those roads.

So far, no states have used the program, but Missouri and Virginia have been given permission to pursue the option, leaving one slot open. Earlier this summer, Rhode Island expressed interest in rehabilitating bridges along Interstate 95 under the pilot program, and North Carolina has too, according to a spokeswoman for the Federal Highway Administration. None of those states has submitted a formal application yet.

Arizona's exploration of the idea has earned far harsher criticism in Utah than in Arizona. One reason is because the stretch is better connected to Utah and Nevada than to most places in the state where it is located.

The "Arizona Strip" of Interstate 15 includes some of the most breathtaking and costly-to-build parts of the interstate highway system. The highway slices through a canyon that links the Mojave Desert to the west with the Colorado Plateau to the east, connecting Salt Lake City to Las Vegas and points beyond, from the Canadian border all the way to San Diego.

There are few alternative routes to the interstate, butit is a stretch of road that few Arizonans ever use. It is cut off from most of Arizona by the Grand Canyon, and creates "little economic benefit to the state," Arizona transportation officials wrote in their federal application ( PDF ). Most of the land around the interstate is owned by the federal government, they wrote, "further diminishing its value to Arizona both today and into the future."

But the road needs major repairs, particularly to some of its bridges that cross the Virgin River Gorge. "The return on investment to Arizona to perform this rehabilitation is negligible, and as such, does not fare well when compared to other high priority projects throughout the state when competing for limited funds," Arizona officials argue. "Consequently, Arizona is proposing to explore a tolling strategy for the Arizona stretch of I-15 to fund this rehabilitation by those users that directly benefit from the existence of I-15."

Utah's governor, though, insists that Arizona has the responsibility to keep up its portions of the national highway system, regardless of how few Arizonans use them. Arizona, just like every other state, Herbert says, receives federal money to maintain the national network. "Arizona cannot pick and choose which parts of our national interstate network it wants to maintain," he said in his statement, "If Arizona has been negligent in its maintenance of I-15, it should not try and foist its responsibility onto highway users or neighboring states who already pay into the system with their own tax dollars."

Ally Isom, Herbert's deputy chief of staff, told Stateline that the governor is concerned with the effect tolls would have on the Utah economy. "Whether or not Utahns are actually traveling this portion of road, we have a lot of freight coming into and going out of the state on this thoroughfare," she said. "This will certainly drive up costs."

A spokeswoman for Nevada Governor Brian Sandoval said Sandoval had not yet addressed the issue, but that his staff is following the application. Timothy Tait from the Arizona Department of Transportation said in an email that any decision is "years" away. In the meantime, Tait added, the state remains committed to keeping I-15 safe.