Michigan → District of Columbia · Interstate 75 / Interstate 94
On heavy-rain or dense-fog days the Detroit, Michigan, to Washington, District of Columbia, leg routinely demands well more than the 7h 7m estimated: Interstate 75 / Interstate 94 carries known hydroplaning hot spots and reduced-visibility corridors that justify dropping to 35 mph through a few short stretches. The outbound run covers 748 km (465 miles) over varied topography between Detroit (the Motor City and historic capital of the American auto industry) and Washington (the capital of the United States and seat of the federal government), demanding sharper attention on mountain descents and shoulder-less curves. Before pulling out, check brake-pad wear, tire tread depth, and washer-fluid level in the reservoir. Fuel spend holds near $62.56 for the 68 liters (18.0 gallons) consumed. Even in adverse conditions, the flat tariff of $0.43/km guarantees the standard outbound payout of $321.64 — log any incidental costs (extra toll, mandatory meal, emergency lodging) in a separate field on the Clara receipt.