When Cuba became a communist threat, the lack of suitable infrastructure for a potentially massive military response and/or invasion from the US was quite obvio

When Cuba became a communist threat, the lack of suitable infrastructure for a potentially massive military response and/or invasion from the US was quite obvious in the southern part of Florida. So the Florida Turnpike was rapidly built to reach from the long-settled part of north Florida, down to the much more isolated and undeveloped resort areas in the Miami area, of which Miami could almost be considered like a suburb of Havana at the time. When Cuba was still a free country it was not thought to be a problem historically if travel between Havana and Miami had always been vastly easier than between Miami and northern Florida. Anyway, it hardly ever snows in Florida, but it does rain a lot and roads can get slick because of that. Taking consideration of visibility, regardless of how overloaded a large truck or convoy may be during emergency conditions, if a constant speed of 100 MPH is maintained, each curve in the Turnpike is gradual, and slightly banked so that regardless of road slickness, vehicles will not skid toward the outside of the curve, nor the inside.