Policy Study

South Dakota Ranks 28th in the Nation in Highway Performance and Cost-Effectiveness

South Dakota’s highway system ranks 28th in the nation in overall cost-effectiveness and condition, according to the Annual Highway Report by Reason Foundation. This is a 19-spot decrease from the previous report, where South Dakota ranked 9th. However, some categories in the report cannot be compared to previous years due to methodological changes that also impacted some state’s overall rankings. These changes are fully explained in Part 2 and the appendix of the full report.

South Dakota ranks in the bottom 10 states nationally in administrative disbursements and structurally deficient bridges. South Dakota’s 2.31 administrative disbursement per lane-mile ratio is 5.1 times higher than peer state North Dakota’s ratio and 9.2 times higher than peer state Nebraska’s ratio. A total 17.30% of the state’s bridges are structurally deficient, which is 1.5 times the percentage of North Dakota’s structurally deficient bridges and two times the percentage of Nebraska’s structurally deficient bridges. 

In safety and performance categories, South Dakota ranks 29th in rural fatality rate, 31st in urban fatality rate, 47th in structurally deficient bridges, 5th in traffic congestion, 4th in urban Interstate pavement condition, and 8th in rural Interstate pavement condition. 

South Dakota is 18th in capital and bridge spending per mile and 36th in maintenance spending per mile.

South Dakota’s best rankings are in urban Interstate pavement condition (4th) and urbanized area congestion (5th).

South Dakota’s worst rankings are in structurally deficient bridges (47th) and administrative disbursements per mile (46th).

South Dakota’s commuters spend 9.8 hours stuck in traffic congestion, ranking 5th nationally. 

South Dakota’s state-controlled highway mileage makes it the 34th largest highway system in the country. 

“To improve in the rankings, South Dakota needs to reduce its administrative disbursements and its percentage of structurally deficient bridges. The state ranks in the bottom five of all states in the country in both categories,” said Baruch Feigenbaum, lead author of the Annual Highway Report and senior managing director of transportation policy at Reason Foundation. “The condition of South Dakota’s roadways seems to have regressed over the past few years.” 

Additional Analysis
Reason Foundation’s Annual Highway Report measures the condition and cost-effectiveness of state-controlled highways in 13 categories, including pavement condition, traffic congestion, structurally deficient bridges, traffic fatalities, and spending (capital, maintenance, administrative, other) per mile.

Compared to nearby states, South Dakota’s overall highway performance is worse than Wyoming (ranks 16th) and Minnesota (ranks 12th), but better than Iowa (ranks 31st). 

South Dakota is doing worse than comparable states such as Nebraska (ranks 26th) and North Dakota (ranks 9th).

In past years, South Dakota has had a similar ranking to its neighbor, North Dakota. Both states had lower overall spending, good pavement quality, and low fatality rates (for rural states). But over the last few years the states have been diverging. While South Dakota’s pavement condition is still good, maintenance and administrative spending have increased. South Dakota ranks in the bottom 15 for both metrics. Further, fatality rates have increased; the state now ranks in the bottom half of all states for all three fatality rates. And South Dakota has not reduced its large percentage of structurally deficient bridges. It has the fourth highest percentage in the country. The state needs to improve bridge quality and to reduce costs to climb back into the top 20. 

South Dakota is one of seven states with an administrative disbursement ratio higher than 2.0. The other six are Vermont, Delaware, New Mexico, Nevada, New Hampshire, and Washington. 

South Dakota is one of nine states that reported more than 10% of their bridges to be structurally deficient. The others are West Virginia, Iowa, Rhode Island, Pennsylvania, Louisiana, Maine, North Dakota, and Michigan.  

South Dakota is one of 25 states that have urban fatality rates of 1.0 per 100 million vehicle-miles traveled or higher. The other 24 states are New Mexico, Florida, Arizona, Tennessee, Louisiana, Mississippi, Wyoming, Delaware, Missouri, Alaska, Kentucky, Hawaii, Alabama, Georgia, Colorado, Oklahoma, Texas, Oregon, Nevada, South Carolina, Pennsylvania, Michigan, Kansas, and Illinois.

South Dakota is one of 24 states that have other fatality rates of 1.5 per 100 million vehicle-miles traveled or higher. The other 23 are West Virginia, Mississippi, Kentucky, Louisiana, South Carolina, Montana, Oklahoma, Oregon, Texas, Kansas, Tennessee, North Carolina, California, New Mexico, Pennsylvania, Washington, Georgia, Maine, Michigan, Missouri, Virginia, Illinois, and Ohio.

South Dakota is one of six states that declined in the overall rankings by at least 10 spots from the previous report. The other states are Oregon, Montana, Kansas, Vermont, and Idaho.

*2021 data
The Annual Highway Report is based on spending and performance data submitted by state highway agencies to the federal government and urban congestion data from the Texas A&M Transportation Institute for 2020 as well as bridge condition data from the Better Roads inventory for 2021. For more details on the calculation of each of the 13 performance measures used in the report, as well as the overall performance measure, please refer to the appendix in the main report. The report’s dataset includes Interstate, federal, and state roads, but not county or local roads. All rankings are based on performance measures that are ratios rather than absolute values: the financial measures are disbursements per mile, the fatality rate is fatalities per 100 million vehicle-miles of travel, the urban congestion measure is the annual delay per auto commuter, and the others are percentages. For example, the state ranking 1st in structurally deficient bridges has the smallest percentage of structurally deficient bridges, not the smallest number of structurally deficient bridges.