Policy Study

Idaho Ranks 34th in the Nation in Highway Performance and Cost-Effectiveness


Idaho’s highway system ranks 34th in the nation in overall cost-effectiveness and condition, according to the Annual Highway Report by Reason Foundation. This is a 26-spot decrease from 8th in the previous report. However, some categories in the report cannot be compared to previous years due to methodological changes that also impacted some states’ overall rankings. These changes are fully explained in Part 2 and the appendix of the full report.

Idaho ranks in the bottom 10 of all states in capital and bridge disbursements, rural arterial pavement condition, and rural fatality rate. The state’s 1.83 capital and bridge disbursement ratio is 1.7 times higher than peer state Montana’s rate and 2.1 times higher than peer state Wyoming’s rate. Idaho’s 3.1% of poor rural arterial pavement condition is two times higher than Montana’s amount and 10 times higher than Wyoming’s amount. Finally, Idaho’s 1.64 rural fatality rate is less than Montana’s rate but 1.2 times worse than Wyoming’s rate. 

In safety and performance categories, Idaho ranks 43rd in rural fatality rate, 3rd in urban fatality rate, 19th in structurally deficient bridges, 7th in traffic congestion, 11th in urban Interstate pavement condition, and 32nd in rural Interstate pavement condition. 

The state ranks 48th in capital and bridge costs per mile and 33rd in maintenance spending per mile.

Idaho’s best rankings are in urban fatality rate (3rd) and traffic congestion (7th). 

Idaho’s worst rankings are in capital and bridge disbursements per lane-mile (48th) and rural arterial pavement condition (46th).

Idaho’s drivers waste 11.3 hours a year in traffic congestion, ranking 7th in the nation. 

Idaho’s state-controlled highway mileage makes it the 41st largest highway system in the country.

“To improve in the report’s overall rankings, Idaho could reduce its capital and bridge spending, and improve its rural arterial pavement condition and its rural fatality rate,” said Baruch Feigenbaum, lead author of the Annual Highway Report and senior managing director of transportation policy at Reason Foundation. “The state ranks in the bottom 10 of each category, and that performance is negating strong rankings in urbanized area congestion, and urban fatality rate.” 

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, Idaho’s overall highway performance is better than Washington (ranks 46th), but worse than Oregon (ranks 37th) and Utah (ranks 10th). 

Idaho ranks below other comparable states, such as Montana (ranks 25th) and others like Wyoming (ranks 16th).

For many years Idaho was a model state ranked in the top 10 of the Annual Highway Report. What was its secret? The state did not have any rankings in the bottom 10 overall, one of just six states with that distinction. But what might have been more impressive is that 10 of the state’s 13 rankings were in the top 25, with one of the other three in the 20s. Idaho was penalized by the change in how the report calculated spending. But the bigger problem was the increase in Idaho’s rural fatality rate and decline in the state’s rural arterial pavement condition. In this report, both rank in the bottom 10. Idaho needs to improve both metrics substantially. 

Idaho is one of six states with a capital and bridge disbursement ratio above 1.50. The other five are Washington, Idaho, New York, Arizona, and New Jersey. 

Idaho is one of five states that reported more than 3% of their rural other principal arterial pavement to be in poor condition. The others are Alaska, Rhode Island, Hawaii, and Maine.

Idaho 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, South Dakota, and Vermont.

*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.