Policy Study

South Dakota Ranks 9th in the Nation in Highway Performance and Cost-Effectiveness


South Dakota’s highway system ranks 9th in the nation in overall cost-effectiveness and condition, according to the Annual Highway Report by Reason Foundation. This is a two spot improvement from the previous report, where South Dakota ranked 11th.

South Dakota ranks in the bottom five states nationally in percent structurally deficient bridges. More than 17% of the state’s bridges are structurally deficient. South Dakota has 1.5 times the percentage of structurally deficient bridges as peer state North Dakota and two times the percentage of structurally deficient bridges as peer state Nebraska.

In safety and performance categories, South Dakota ranks 21st in overall fatality rate, 47th in structurally deficient bridges, 12th in traffic congestion, 15th in urban Interstate pavement condition, and 10th in rural Interstate pavement condition.

South Dakota spends $27,629 per mile of state-controlled road. South Dakota is 4th in total spending per mile and 4th in capital and bridge costs per mile.

South Dakota’s best rankings are in total disbursements per mile (4th) and capital and bridge disbursements per mile (4th).

South Dakota’s worst rankings are in structurally deficient bridges (47th) and rural arterial pavement quality (29th).

South Dakota’s commuters spend 5.83 hours stuck in traffic congestion, ranking 12th 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 percentage of structurally deficient bridges. The state has the fourth largest percentage of structurally deficient bridges in the country,” said Baruch Feigenbaum, lead author of the Annual Highway Report and senior managing director of transportation policy at Reason Foundation. “South Dakota ranks in the top 30 states in all 10 of the remaining metrics and in the top 10 in five of the metrics including three of the four disbursement categories.”

Additional Analysis

Compared to nearby states, South Dakota’s overall highway performance is better than Wyoming (ranks 12th), Minnesota (ranks 18th), and Iowa (ranks 22nd).

South Dakota is doing better than some comparable states like Nebraska (ranks 21st) but worse than others such as North Dakota (ranks 1st).

Similar to other states that rank in the top 10, South Dakota is able to offer smooth pavement quality at a low overall cost. Similar to its neighbor, North Dakota, what sets the state apart is its low overall fatality rates. The state’s 13.7 is the second lowest overall composite fatality rate for a large-geographic-area-small-population state (North Dakota’s is 13.3). These types of states tend to struggle with fatality rates because motorists are traveling faster and speed is a major factor in fatalities. Not only does South Dakota excel in categories in which it may have an advantage such as cost, it does well in categories where it may have a disadvantage such as fatality rate. If the state could reduce its percentage of structurally deficient bridges, it might move into the top five in the rankings.

South Dakota is one of five states that reported more than 15% of their bridges are structurally deficient. Rhode Island, West Virginia, Iowa, and Pennsylvania are the other four.
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, total) per mile.