Generated Traffic and Induced Travel: Implications for Transport Planning

Traffic congestion tends to maintain equilibrium; traffic volumes increase to the point that congestion delays discourage additional peak-period trips. If road capacity increases, peak-period trips also increase until congestion again limits further traffic growth. The additional travel is called “generated traffic.” Generated traffic consists of diverted traffic (trips shifted in time, route and destination), and induced vehicle travel (shifts from other modes, longer trips and new vehicle trips). Research indicates that generated traffic often fills a significant portion of capacity added to congested urban road. Generated traffic has three implications for transport planning. First, it reduces the congestion reduction benefits of road capacity expansion. Second, it increases many external costs. Third, it provides relatively small user benefits because it consists of vehicle travel that consumers are most willing to forego when their costs increase. It is important to account for these factors in analysis. This paper defines types of generated traffic, discusses generated traffic impacts, recommends ways to incorporate generated traffic into evaluation, and describes alternatives to roadway capacity expansion.

• Record URL:
  http://www.vtpi.org/gentraf.pdf
• 
• Supplemental Notes:
  • © 2017 Todd Litman.
• Corporate Authors:

  Victoria Transport Policy Institute

  Victoria, British Columbia  Canada 
• Authors:
  • Litman, Todd
• Publication Date: 2017-7-18

Language

• English

Media Info

• Media Type: Digital/other
• Features: Figures; References; Tables;
• Pagination: 39p

Subject/Index Terms

• TRT Terms: Analysis; Automobile travel; Highway capacity; Impacts; Traffic congestion; Transportation planning
• Subject Areas: Highways; Operations and Traffic Management; Planning and Forecasting;

Filing Info

• Accession Number: 01652452
• Record Type: Publication
• Files: TRIS
• Created Date: Nov 30 2017 9:51AM