It’s been a bumpier ride out there, and Louisiana’s designation of 40th in the nation for road conditions marks a significant deterioration of the roads and the ranking.

The highway report by the libertarian Reason Foundation graded roads on 2012 data, the latest available, but Louisiana’s ranking was significantly down by several measures. Pavements on urban interstates are better than only two other states.

Of the 50 states, Louisiana ranks 44th in its highway fatality rate, 41st in the condition of rural interstate pavements and 39th in the number of deficient bridges.

David T. Hartgen, the author of the study, said the state’s rating was also hurt by a drop in its spending for highway maintenance. “So a bigger problem and less money to work with yields a drop in the ratings,” Hartgen said in an interview.

The state was ranked 24th in highway conditions and spending effectiveness by the same group in 2011.

That’s a stiff drop, and part of it is likely because other states are spending more in repairs as their economies recover from the 2008 market crash and ensuing recession.

Hartgen said the ranking dropped in part because urban interstate mileage rated as poor rose from 8.7 percent to 15.3 percent, which is three times the national average. The only states whose urban interstate pavements were rated as worse than Louisiana are California and Hawaii.

Rural interstate mileage classified as poor shot up from less than 1 percent to 4 percent, which is about double the national average.

“In just one year the backbone, if you will, of the Louisiana highway system registered a very significant uptick in the percent of poor mileage,” he said.

“It is easily a yellow flag and maybe a red flag,” Hartgen said of the drop in interstate pavement conditions.

Rodney Mallett, a spokesman for the state Department of Transportation and Development, said the state has invested $6.4 billion in highway improvements since 2008, including more than $1.8 billion to improve key interstate corridors. While Mallet is quite correct, the figure is a bit misleading, as the pre-recession windfall of revenues allowed the state in 2008 to put a lot of projects underway.

The state doesn’t have funding to keep that pipeline full. For politicos, the credit back home comes mostly from expanding capacity, building new roads or adding lanes. A responsible level of spending on repair and resurfacing is not as politically attractive, and raising the gasoline tax has been a political non-starter.

Louisiana’s geology is also naturally challenging for road building and for maintenance, a fact that influences any attempt at an apples-to-apples comparison with other states.

The fault as we see it is less at DOTD than from decision-makers at the State Capitol and in the Governor’s Mansion.

Enjoy the ride, such as it is, because even if new money can be found, maintenance expenditures will take a couple of years to get into gear.