This document discusses a report on applying probability to control traffic flow through a highway system. It first defines key probability terms like events, sample space, mutually exclusive events, and independent events. It then provides an example calculation of probability by finding the probability of an even sum when rolling two dice. Finally, it describes a proposed probabilistic model for modeling lane changing behavior on highways based on drivers' desired speeds and safety constraints like the two-second rule for following distances. The aim is to provide a simple yet accurate representation of lane changing behavior to help control overall traffic flow.