Math Artifacts

AnyTown has a population of $4$ million people who use $6$ major east-west freeways, each of which has $5$ lanes of traffic in each direction. The freeway speed limit is $65$ miles per hour ($105$ km/hr) and everyone follows the safety rule of a "$1$ second following distance" between each car. Even with the safety consciousness, traffic jams cause the average commute to work to be $30$ minutes. During the $8$ a.m. to $10$ a.m. rush hour, what is the maximum number of cars that can exit eastbound from one of the $6$ freeways?