PROPAGATION OF DISTURBANCES IN TRAFFIC FLOW

The system-optimized static traffic-assignment problem in a freeway corridor network is the problem of choosing a distribution of vehicles in the network to minimize average travel time. It is of interest to know how sensitive the optimal steady-state traffic distribution is to external changes including accidents and variations in incoming traffic. Such a sensitivity analysis is performed via dynamic programming. The propagation of external perturbations is studied by numerical implementation of the dynamic programming equations. When the network displays a certain regularity and satisfies certain conditions, we prove, using modern control theory and graph theory, that the effects of imposed perturbations which contribute no change in total flow decrease exponentially as distance from the incident site increases. We also characterize the impact of perturbations with nonzero total flow. The results confirm numerical experience and provide bounds for the effects as functions of distance.

• Corporate Authors:

  Massachusetts Institute of Technology

  Electronics Systems Laboratory
  Cambridge, MA  United States 

  Transportation Systems Center

  55 Broadway, Kendall Square
  Cambridge, MA  United States  02142
• Authors:
  • Dersin, P
  • Gershwin, S B
  • Athans, M
• Publication Date: 1977-9

Media Info

• Pagination: 292 p.

Subject/Index Terms

• TRT Terms: Control; Crash investigation; Dynamic programming; Forecasting; Freeways; Network analysis (Planning); Networks; Optimization; Perturbation theory; Perturbations; Roads; Sensitivity; Stochastic processes; Traffic; Traffic assignment; Traffic distribution; Traffic engineering; Traffic flow; Traffic incidents; Travel time
• Uncontrolled Terms: Incidents; Network flows
• Old TRIS Terms: Propagation
• Subject Areas: Data and Information Technology; Highways; Operations and Traffic Management; Safety and Human Factors;

Filing Info

• Accession Number: 00168996
• Record Type: Publication
• Source Agency: National Technical Information Service
• Report/Paper Numbers: DOT-TSC-OST-77-62 Final Rpt.
• Contract Numbers: DOT-TSC-849
• Files: NTIS, TRIS
• Created Date: Jan 30 1978 12:00AM