CDOT Performance Data Business Plan - Cambridge Systematics

CDOT Performance Data Business Plan
Section 3 of this report recommends three measures related to congestion – one
based on the percent of person miles traveled (PMT) on congested corridors, one
on person delay, and another one based on travel time reliability. The first
measure is designed to work with CDOT’s existing data, and CDOT is working
to develop the second and third. The first measure is based on comparing a
highway segment’s traffic volume to its capacity. Developing a cost/benefit
curve would require estimating the change in a highway segment’s capacity that
could be achieved by implementing a project. This calculation is relatively
straightforward for capacity expansion projects but not technically feasible for
operations projects.
Given that the mobility curve should focus on operations projects and that it is
not possible to relate operations projects directly to a highway’s capacity, it is
recommended that CDOT hold off on developing a mobility cost/benefit curve
until a measure of reliability is developed.
When the details of delay and reliability measures have been resolved, a
cost/benefit curve could be developed using a project-level approach. This
approach would require CDOT to define a list of potential operations projects
and to estimate the following information for each:
Project cost;
Value of the reliability measure on the project segment without the project;
and
Value of the reliability measure on the project segment with the project.
In addition, the projects would need to be ranked from highest to lowest priority.
The prioritization could be done based on cost effectiveness (e.g., change in
reliability per dollar) or using a more comprehensive approach. Once the list has
been prioritized, a cost/benefit curve could be created as follows:
Assume a funding level;
Work down the list of prioritized projects until these funds are expended;
Calculate the cumulative change in reliability expected for the funded set of
projects;
Plot the resulting value; and
Repeat this process for additional funding levels.
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