The Interstate Highway System was deliberately designed with 10-foot-wide lanes instead of the standard 12 feet used by most state highways, a cost-saving measure that Eisenhower’s administration later regretted because the narrower lanes created measurably higher accident rates during bad weather—yet by then hundreds of miles had already been constructed to the substandard width, making a nationwide retrofit economically impossible and effectively locking in a permanent safety compromise across the entire national road network.
Car Fact #115 — October 9, 2026
