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How road conditions in Illinois have deteriorated since 2000

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February 9, 2024
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How road conditions in Illinois have deteriorated since 2000

The United States boasts an impressive interstate network of 4.2 million miles of roads—but underlying that reputation is a backlog of $786 billion in needed repairs, according to the American Society of Civil Engineers. On average, the society estimates, American motorists spend a collective $130 billion on extra vehicle repairs and fuel costs as a result of driving on poor-quality roads and bridges.

In 2000, 82.6% of U.S. roads were considered acceptable to drive on, according to federal standards, which look at how rough or smooth a road surface is based on how much vibration a car's suspension has to absorb while driving on it. By 2020, a smaller share—81%—of U.S. roads were rated acceptable. used Bureau of Transportation Statistics data to analyze how road conditions in Illinois have changed over the past two decades, as part of a larger analysis of U.S. road conditions. The analysis considers the change in the share of roads considered to be in acceptable condition.

In 2000, over 90% of the roads in Illinois were rated as being in acceptable condition. By 2020, that share had dropped by about 10 percentage points. Illinois spends $123,522 per state-controlled mile of highway, ranking 39th nationally for total disbursements per mile.

Road condition is determined by the International Roughness Index, which measures deviations from pavement surfaces significant enough to affect driving. Roads with IRI values below 170 are considered to be in acceptable condition, while anything above 170 is considered poor condition. Data represents the percentage point change from 2000 to 2020.

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Fewer roads are in acceptable condition in 2020

Across the country, the change in the share of roads in acceptable condition over the past two decades does not appear to be a significant downgrade. However, the nationwide change can be misleading because while some states have improved their road infrastructure, some states have seen a massive decrease in road quality.

States like Rhode Island and Washington have seen over 20% of their roads degrade into poor condition. Other states, including Arkansas and Oklahoma, have conversely seen significant improvements in the quality of their roadways, and are planning to invest more by implementing state-initiated projects and tax hikes. California, which has seen road conditions improve, depends on higher-than-average gas taxes to fund road repair and construction. To learn more about changing road conditions in each state, read the national analysis.

This story features data reporting by Paxtyn Merten, writing by Colleen Kilday, and is part of a series utilizing data automation across 51 states.

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