An inspector general's report said Chicago Department of Transportation officials should be more proactive in plugging cracks before they grow into menacing potholes. View Full Caption DNAinfo/Jackie Kostek

CHICAGO — City administrators need to rethink the way they decide which potholes to fill, Chicago's inspector general says.

In a 15-year audit of the Chicago Department of Transportation, released last week, Chicago Inspector General Joseph Ferguson found that the way the city prioritizes street repaving projects wastes millions of dollars and sometimes relies on the level of public outrage rather than data.

CDOT has traditionally fixed the worst potholes on arterial streets first, which may seem intuitive, but experts say it's better to focus on preventing roads from deteriorating. Diverting more city funding toward sealing cracks before they become gaping chasms, the report estimated, would save CDOT about $4.6 million per year.

Additionally, since 2000, the department has "lacked sufficient street condition data" to properly prioritize its street repaving projects, the report said.

CDOT spokesman Mike Claffey released a statement in response to the report, noting that while the inspector general's audit of the department goes back 15 years, the department began seriously revamping its approach to street repair starting in 2013.

CDOT officials surveyed almost 3,000 miles of arterial streets for damage in 2014, Claffey said, with plans to repeat the survey every three years from now on. That survey was only taken once between 2000 and 2014, the inspector general's report found.

Also in 2013, the department started a "crack seal program" as a way of shifting to the more proactive approach recommended by the inspector general, Claffey said.

Claffey gave no response, though, to another criticism that surfaced in the report: While repairs of main streets are prioritized based on survey data, it's still ultimately up to aldermen to decide when holes get plugged on residential streets.

Through the Aldermanic Menu Program, each ward has about a $1.32 million flexible budget for public services, including street re-paving, according to the inspector general's report. Aldermen's decisions over how that money is doled out may ignore empirical data in favor of which constituents complain the loudest, Ferguson warned.

"For practical purposes, this means that the Department uses lower quality data and manages residential streets as a separate system from arterial streets," read a written statement accompanying the release of the report. "Therefore, the City’s street maintenance is not optimized at the network level for the fiscal health of the City as a whole."

But Ald. Ricardo Muñoz (22nd) disagreed, saying his Little Village constituents were better surveyors of their own streets than any citywide program could be.

“Whether or not it’s efficient, neighbors don’t really want to hear about that,” Munoz told CBS Chicago. “They want their street fixed.”

For more neighborhood news, listen to DNAinfo Radio here: