Don’t look now, but North Carolina’s long-maligned highway system is showing signs of significant improvement.

Actually, do look now. Look at a just-released set of infrastructure grades from the American Society of Civil Engineers (ASCE). The 2013 report gives North Carolina a C for roads, which is up from a D- in 2009 and higher than the 2013 national average of a D. On bridges, North Carolina stayed at a C-.

ASCE is hardly a neutral party. Because it represents an industry sector that stands to benefit if governments spends more money on capital projects, its infrastructure grades should at least be understood as less than a rosy scenario. Still, other analysis of federal statistics on highway capacity, condition, and safety also show that North Carolina’s surface-transportation network is in better shape than it used to be.

In July, for example, Dr. David Hartgen and several co-authors released the 20th in an annual series of performance rankings for state highway systems. Hartgen is a professor emeritus of transportation studies at UNC-Charlotte and the author of several JLF studies of North Carolina’s transportation policies. In fact, JLF published Hartgen’s annual ranking for several years. The project is now produced for a national audience by the Reason Foundation.

As recently as 2005, North Carolina ranked 31st out of the 50 states in highway performance, a metric that includes a number of measurements of condition, congestion, safety, and efficiency. But according to the latest rankings (based on the latest year of comparable data, 2009) North Carolina ranks 19th in highway performance. It was a dramatic gain, reflecting the completion of several long-delayed highway projects and, to give credit where it’s due, managerial improvements in the N.C. Department of Transportation under the late Easley and Perdue administrations.

Since 2009, the state has completed several additional major projects of road expansion and maintenance, including a public-private toll road in Wake County. Others are in mid-construction. It seems likely that North Carolina’s national ranking would continue to improve a bit even if nothing else was done.

Fortunately, the McCrory administration and General Assembly have done something else of note. During the just-completed legislative session, they re-wrote North Carolina’s transportation-funding formula to put a greater emphasis on traffic congestion, economic growth, and highway safety. Hartgen was among several respected transportation-policy experts who praised the 2013 legislation for moving North Carolina’s system in the right direction.

Of course, to be improved is not to be adequate. North Carolina continues to have unmet transportation needs, even if we discount ASCE’s projections as inflated. Over time, state tax revenues from the sale of motor fuels and cars have not kept up with highway usage. It’s the flipside of good news for consumers. On average, vehicles have become more durable and efficient. The resulting reductions in fleet turnover and fuel consumption translate into fewer car and gas tax dollars per mile traveled. At the very least, these trends argue for continuing to find efficiencies in the Department of Transportation, dedicating all gas and car tax revenues to road and bridge projects, and using tollways to add new highway capacity in parts of North Carolina where it makes sense to do so.

Remember that whatever economic benefits come from infrastructure investment flow from what gets built where, not how many tax dollars are spent in the process. In my growing database of academic research on state economic growth, there is an interesting pattern: while more than two-thirds of peer-reviewed studies find that the stock or quality of state or local infrastructure is positively related to economic growth, only 44 percent of studies find that government spending on infrastructure brings net economic benefits. In other words, unless infrastructure projects are sited wisely and completed efficiently, the boost in mobility or productivity they may bring are offset by the economic cost of the taxes required.

Because bad news is good news, positive trends rarely get the attention they deserve. According to two recent national studies, North Carolina has made substantial progress in the management of our highway system. Let’s keep it up.

Hood is president of the John Locke Foundation.