Arizona needs to change its model for funding road and street building and maintenance because the current system based on gasoline taxes doesn't work, governmental officials and advocates say.

The state gasoline tax, in use as the main source of money for transportation since 1921, brings in insufficient revenues to cover needed costs and has been subject for years to legislative takeaways for other needs, those officials say. The fund started at 1-cent a gallon and is now 18 cents, a level that has not changed in 22 years.

In addition, because people drive less when gasoline prices are high, as is occurring now, and because they are driving fuel-efficient and alternative-fuel vehicles, the tax no longer serves as a true user fee, they say.

Suggestions replacements or augmentations include taxing vehicles by miles traveled and by weight, because heavier vehicles put more wear and tear on roads.

For this fiscal year, the Legislature ordered $86 million of Highway User Revenue Fund receipts diverted to cover spending in the Department of Public Safety and the Motor Vehicle Division. For the 2012-13 fiscal year, the amount will be $120 million diverted for DPS, said Ken Strobeck, executive director of the League of Arizona Cities and Towns.

"When the public is filling their gas tank, they're expecting that 18 cents worth of gas tax is going to pay for the streets and roads," Strobeck said in an interview for Friday's Arizona Week.

He estimated that Arizona cities and towns have lost $204 million in transportation funding through legislative "sweeps" in the last decade of money from the fund, known by its acronym HURF. He further estimated that counties lost $127 million and the State Highway Fund $337 million.

Money lost to all Arizona cities and towns in the last decade would more than pay for one major project on the books in Tucson, the five-mile Grant Road widening to six lanes. Its current estimated cost is $167 million, and it will be paid for mostly with money from the Regional Transportation Authority's half-cent sales tax fund, not with money from HURF.

In Pinal County, road operations have lost more than $5.4 million between 2009-2012 from sweeps, Assistant County Manager Greg Stanley said in an Arizona Week interview. Stanley said that amount is enough to allow the county to cover the first phase of its top priority road project, improving Hunt Highway through San Tan Valley.

"The San Tan Valley area between the 2000 and 2010 Census, their growth was over 3,000 percent," Stanley said. "So they're up to around 81,000 people in the last census, and the road network is not there to support it."

State Rep. Vic Williams, R-Tucson, as chair of the House Transportation Committee this year introduced legislation that would have begun an accounting process for the HURF sweeps.

He said holding the Legislature accountable for the amount being taken from road work was important, and he called it a first step reforming the system.