Why are alkali flats in the western United States important for automobile speed records?

Alkali flats, which are a type of playa or dried-out desert lake, are ideal for automobile speed records because of their unique physical characteristics. Specifically, sites like the Bonneville Salt Flats in the western United States provide an extremely level and smooth surface.12

By the end of the summer, these flats become as solid as concrete, creating a stable, expansive terrain perfectly suited for high-speed trials. These features are remnants of ancient lake beds, such as the prehistoric Lake Bonneville, which left behind vast, flat deposits of salt and clay. Because of this combination of flatness, smoothness, and hardness, these environments have been used for decades to establish numerous world automobile and motorcycle speed and endurance records.13452