Blog Post

How Bad is the Nation’s Transportation Infrastructure, and What are Future Spending Needs?

May 29, 2015 | Alan J. Krupnick, Virginia McConnell, William Raich

In last week’s blog post, we described the current dilemma in funding the Federal Highway Trust Fund (HTF). Congress just passed another in a long series of short-term extensions for surface transportation funding, but a long-term solution is what is needed. In this entry, we provide additional context for the problem by giving an overview of the current state of roads and bridges in the United States. We then review estimates of how much funding is projected to be needed in the future.

There is no consensus for assessing the quality and performance of the nation’s roads or bridges, but there are a number of measures that can provide benchmarks. The general picture, contrary to popular opinion, is that the quality of both roads and bridges has been improving nationwide over the last 25 years, but a good deal of infrastructure remains in fair or poor condition. In addition, there is a great deal of heterogeneity across states in the quality of roads and bridges. Finally, roadway congestion has become a significant problem in many urban areas, but congestion levels have fallen recently in many cities.




Figure 1. Bridge Conditions by CountyBridges. Federal Highway Administration (FHWA) data shows that the number of bridges listed as structurally deficient has halved since 1992, with roughly 9,000 bridges removed from the structural deficiency list since 2010. Despite these marked improvements, there remains a significant backlog of improvement projects nationwide – a quarter of bridges remain rated as either structurally deficient or functionally obsolete, and many are over 50 years old. Former Transportation Secretary Ray LaHood explained, “[structurally deficient bridges] need to be really either replaced or repaired in a very dramatic way … I don’t want to say they’re unsafe, but they’re dangerous.” Overall, ARBTA reports that more than $115 billion in bridge work awaits funding.


With over 60,000 structurally deficient bridges nationwide—roughly a tenth of the total—there is a great deal of variation in bridge conditions across states and counties. Figure 1 captures this variation, displaying the percent of bridges in each county rated as structurally deficient. Counties with fewer than ten bridges are omitted from the analysis. Traffic volume, weather conditions, age of bridges, and previous maintenance are among the factors that play a role in the condition of bridges across states.

Roads. In 2012, just over 20 percent of the nation’s federally funded highways were in poor or mediocre condition and needed repaving or even more substantive repairs. Highways in urban areas are in worse condition than elsewhere because they tend to carry more traffic. The nation’s Interstate highways are in relatively good condition, with only 1.8 percent of rural miles and 5.0 percent of urban miles in poor or mediocre repair. The trend over time in road conditions is mixed, with some states improving over time, and others showing further deterioration.

The problem of congested highways has been concentrated in the largest urban areas, but there is evidence that congestion problems have also spread to smaller cities in recent years. For decades growth in VMT (vehicle-miles traveled) outpaced the expansion of the highway system, establishing a long-term trend of increasing congestion in US cities. However, there has been improvement in most urban areas since 2008, likely due to the combined effects of the dramatic decline in VMT growth during the recession and increased road spending under the Federal-Aid Highway Program and the stimulus package. Whether congestion levels continue to improve will depend on whether VMT levels return to previous levels or whether there have been structural changes in driver preferences and demographics. Government policy and spending will also be important. Congestion problems tend to occur at specific times and places, so targeted policies and spending are needed, as we discuss further in a later entry in this blog series.

It is useful to identify which types of projects the federal HTF funds. Less than 20% of Federal-Aid Highway funding for new projects in 2011 went towards expanding the highway system, either through building new roadways or adding lanes to existing highways. A much larger portion is directed towards maintenance and repair. This is consistent with spending levels in previous years and reflects the significant costs of maintaining current infrastructure.

Going forward, what does the spending picture look like? The need for maintenance, repair, and expansion of transportation infrastructure in the future will require consistent funding sources. Whether current funding levels are adequate for addressing these needs is a question that must be answered. Figure 2 outlines four scenarios FWHA has developed for future Federal-Aid Highway spending, which in the past has included spending from the HTF, as well as some additional federal and state funding. From 2008 to 2010 this amount was roughly $70 billion, with additional funds coming from The American Recovery and Reinvestment Act of 2009. FHWA’s Maintain Conditions and Performance Scenario (the first bar in Figure 2) would spend just enough to keep conditions in the system constant, including the current shortfalls outlined in this blog. The next two scenarios would improve upon the current performance level based on estimated benefit cost ratios (the second and third bars). The final bar shows spending levels needed if only rehabilitation projects with net benefits are implemented, ignoring system expansion. The annual investments required by the four scenarios vary greatly, but in all cases, there is a need for stable revenue generation.



Figure 2. DOT (2013) Federal-Aid Highway Spending ScenariosThe public and its leaders need to decide what level of road performance and spending is acceptable and, while not discussed above, how large the federal role should be compared to the states and the private sector. In the next several blogs, we examine various policies for raising funds for transportation infrastructure.