Although molecular clock theory is a commonly discussed facet of evolutionary biology, undergraduates are rarely presented with the underlying information of how this theory is examined relative to empirical data. Here a simple contextual exercise is presented that not only provides insight into molecular clocks, but is also a useful exercise for demonstrating how statistical processes are involved in modeling biological phenomena. The example given involves studying rate variation in traffic flow; a variety of other cases will be just as useful, and can provide founding material for further discussion of how molecular clock models are useful in basic and applied biology. (Contains 4 figures and 1 table.)