New roads generate substantial new traffic in metropolitan regions. A 1.0 percent increase in lane miles induces a 0.9 percent increase in VMT within five years. With so much induced traffic, adding road capacity does little to reduce congestion. However, the aggregate relationships presented here may not hold for an individual highway project. Now, we must seek convergence between macro-studies such as this one and more detailed and elaborate planning models that can predict the effects of specific road improvements. Without further and complementary macro- and micro-analyses, our ability to assess urban transportation improvements will remain limited. But at least in metropolitan areas, it seems that the Law of Traffic Congestion has been upheld.


  • English

Media Info

  • Pagination: p. 16-22
  • Serial:
    • Access
    • Issue Number: 7
    • Publisher: University of California Transportation Center (UCTC)

Subject/Index Terms

Filing Info

  • Accession Number: 00715474
  • Record Type: Publication
  • Files: TRIS
  • Created Date: Jan 16 1996 12:00AM