For example, adding an urban highway lane typically accommodates about 2,000 additional daily vehicle trips. 2 Although this reduces congestion on that roadway (at least temporarily, until generated traffic fills the capacity), it often increases “downstream” surface street traffic congestion, increases parking demand, requires travelers to own and operate automobiles, and if additional vehicle travel is induced it increases accidents, energy consumption, pollution and sprawl, all costs that could be reduced if the same trips are made by alternative modes. Residents of multi-modal communities tend to spend less on transportation overall, as illustrated in Figure 5, savings $1,000 to.
