Transportation projects and services are typically implemented with the objective of lowering congestion, increasing safety, and decreasing travel time such reductions in user costs translate into increases in quality of life, business productivity, retention and attraction of investments, increased employment, and so on. However, an increase in transportation supply does not always lead to a decrease in total travel costs. Depending on the shape of the demand and supply functions and the elasticity of demand, a decrease in unit travel costs could lead to a decrease or increase in total user costs (Dickey and Miller,1984) For example, Figure 4.5 shows that (1) the benefits of the transportation system improvement (the area DCBF) are not necessarily equal to the change in total user costs (the area ODFG – the area OCBH), and (2) the total user costs in this scenario actually increases with the decrease in unit travel costs due to the system improvement (the area represented by rectangle ODFG is much larger than that represented by rectangle OCBH)