More than two-thirds of the states lack adequate ways to measure whether their transportation spending achieves economic, mobility, environmental, infrastructure quality and other goals, says a new report from two policy research groups.

The study, released on May 10 by the Pew Center on the States and the Rockefeller Foundation, found that only 13 states have goals, performance measurements and data to help their transportation officials set spending priorities effectively.

It adds that 19 states fall short in those areas and 18 states and the District of Columbia show mixed results.

With federal and state transportation spending under pressure, quantifying and verifying transportation projects' bang for the bucks spent could become a part of the new multi-year surface transportation bill that congressional committees are drafting.

Robert Zahradnik, the Pew Center's director of research, says, "Unless states have clear goals, performance measures and data to generate that information. It is very difficult for policy makers to prioritize transportation investments effectively, target scarce resources and help foster economic growth."

State transportation agencies support federal legislation that calls for measuring whether projects meet nationwide goals, says John Horsley, the American Association of State Highway and Transportation Officials' executive director.

He adds, "States want to see broader use of performance measurement in how they manage their programs at home, and to document for Congress what is being achieved nationwide."

Horsley notes that state transportation departments don't use some of the yardsticks evaluated  in the Pew-Rockefeller report, but adds that the agencies have measured project results systematically for many years.

The Pew-Rockefeller study looks at six areas in which highway and transit projects have impacts. The report gives states the highest scores in safety performance measurement, noting that all states compile information on fatalities and accidents.

States also do well in assessing projects' infrastructure-preservation results, with more than three-fourths of states getting top grades from the report's authors.

But only 16 states get top grades in assessing projects' impact on creating jobs and promoting commerce.