New Jersey got the lowest marks - again - in a study of how effectively states spend their highway money.

New Jersey has ranked last since 2000 in the annual report on highway performance by the Reason Foundation, a Libertarian think tank.

Pennsylvania ranked 36th, the same spot it had last year.

The study evaluated how much states spent on roads and how they compared in such categories as pavement and bridge condition, traffic fatalities, and congestion.

"It's the question your mom would ask: 'How much did we give them, and how did they use it?' " said the main author of the study, David Hartgen, a retired professor of transportation studies at the University of North Carolina at Charlotte.

States were ranked poorly if their spending was high and their congestion and safety were low.

That put densely populated states at a disadvantage, since they spent more and their roads were more heavily used. New Jersey is the nation's most densely populated state.

Top-ranked in the study were North Dakota, Montana, New Mexico, Wyoming, Kansas, South Carolina, South Dakota, Nebraska, Kentucky and Georgia.

New Jersey ranked well in safety, at seventh best in the rate of highway fatalities. But it was the nation's biggest spender per mile and among the worst in congestion. The report said its highway maintenance cost $145,000 per mile, compared with a national average of $21,000.

"Very high unit costs relative to other states, in combination with heavy traffic, more than offset low accident rates and rural primary pavement condition," the report said.

Erin Phalon, spokeswoman for the state Department of Transportation, disputed the study's characterization of New Jersey as cost-ineffective.

"The Federal Highway Administration recently recognized NJDOT for generating the most cost savings on construction design of any state in 2007," Phalon said. "NJDOT's days of building the Cadillac model of infrastructure improvements are long gone, and our focus is on maximizing our resources and making cost-effective decisions."

Phalon said the report did not consider the state's high construction costs, antiquated infrastructure, or spending on mass transit.

In Pennsylvania, the worst rankings were for the state's deficient bridges (49th place). It was in the middle of the pack in most other categories, including 24th in the highway-fatality rate.

PennDOT spokesman Richard Kirkpatrick said Pennsylvania is hampered by the size and age of its highway system, but he noted that Gov. Rendell has been a national leader in advocating more money for bridges and other transportation infrastructure.

"Dr. Hartgen has made clear what is important in his rankings: states with systems in good condition and with 'relatively thin budgets,' " Kirkpatrick said.

"Meeting those two criteria is a difficult challenge for a state like Pennsylvania," he said. "We have a big, old system that we are working hard on improving. That mission takes enormous resources."

Hartgen acknowledged yesterday that states such as New Jersey and Pennsylvania suffered in his rankings because of population density, tough weather conditions, and heavy truck traffic, as well as high construction costs.

He said high-performing states focused on spending their money where it could make the biggest difference for the most people.