Resources for Students and Instructors

Academic Case Studies: Travel Time Based Performance Measures Class Problem


The Transportation Secretary of Factiousville has given you the responsibility to create an ordered list of bottlenecks in Factiousville that should be invested in order to mitigate congestion. You will be provided a map of the city with the eligible bottlenecks and more detailed information about each bottleneck including its histogram and volume.


  1. For each bottleneck:
    1. Create a cumulative distribution function (CDF) graph with 5% resolution
    2. Calculate the:
      1. Travel Time Index (TTI)
      2. Planning Time Index (PTI)
  2. Rank the bottlenecks from 1 (bottleneck that justifies immediate investment) to 5 (bottleneck that can wait for improvements) based on the performance measures you calculated and for other reasons (volume not high enough, do not want to cause urban sprawl, etc.)
  3. Write a narrative at least 1 page (double space) in length justifying your rankings. Feel free to mention other projects around the US as examples.

map - TPM class problem

A. Lakefront Freeway

lakefront freeway - TPM class problem
Picture Source: the University of Wisconsin System

B. Central Y Interchange

central Y interchange - TPM class problem
Picture Source: Google Maps

C. Cloverleaf Interchange

cloverleaf interchange - TPM class problem
Picture Source:

D. Exurb to City Freeway

exurb to city freeway - TPM class problem
Picture Source: Google Maps

E. Factiousville Beltway

Factiousville beltway - TPM class problem
Picture Source:

For more information, contact:

Michelle Noch
ITS Professional Capacity Building Program Manager
ITS Joint Program Office
U.S. Department of Transportation


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ITS Help Line - The ITS Help Line provides technical support by email or telephone at 866-367-7487.


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