Evaluating Alternative Operations Strategies to Improve Travel Time ...

SHRP 2 L11: Final Report
Operational improvements, such as more-efficient traffic-signal timing, are not as publicly visible
as new construction and thus are not valued as highly as other public expenditures, even though
the overall benefit-to-cost ratio might be higher for operational improvements. This lack of
resources is a false savings made possible only by externalizing the cost of disruptions to the
public in the form of increased delay. For example, many planned special events reimburse
highway agencies for the costs of traffic control for their events. The costs of additional traffic
operations measures on roadways leading to the event site are often borne by the roadwayoperating
agency.
If an agency lacks the resources to implement these operational measures, then the cost is borne by
roadway users who experience additional delay and, possibly, accidents. This cost scenario is the
same for unplanned special events and recurring congestion. Agencies are also hampered by
regulations that discourage creative ways to use resources (staff/equipment) that could be available
for incident response or special events. Considerable improvement in access to equipment and staff
could be gained if agencies were able to more-effectively share resources (and otherwise
cooperate) with other agencies.
Ability to Predict Disruptions
“Unreliable” conditions are caused by unusual events that reduce roadway capacity or increase
traffic volumes. If these conditions can be predicted, steps can be taken to mitigate the change in
conditions or prevent the change in the conditions. This preparation often reduces the resources
needed to respond to the disruption after the fact. Prediction of unusual conditions can be based on
historical conditions that are rather predictable. For example, Memorial Day weekend has high
traffic volumes, so placing incident-response vehicles on duty that weekend can dramatically
reduce the effect of incidents on travel-time reliability. Prediction of unusual conditions can also
be based on (a) a network analysis of key locations where responses are most effective, or (b)
analytical factors extracted from other geographic areas that describe the conditions under which
unreliable travel occurs.
Access to Tools/Techniques
Once an event/disruption occurs or is identified as “about to occur” (such as when a construction
event is being planned), the ability to restore reliable travel conditions is a function of an agency’s
ability to quickly implement the appropriate response. This means that the agency needs to:
• Understand the nature of the event/disruption;
• Understand what actions/resources are required to deal with that event/disruption;
• Have access to the necessary resources;
• Be able to take the necessary actions (permission is a big issue here); and
• Possess the appropriate management capabilities to apply the necessary resources/actions
in the right places, at the right times, and in the right way.
The quality of execution matters as much as the actual effort expended. Keys to the above tasks are
the existence of institutional arrangements that allow:
• Agencies to access and share resources;
• Functional, multi-agency protocols for working together;
• Interagency working arrangements that are region-wide, not simply limited to neighboring
jurisdictions;
• Training for staff to ensure that these protocols work effectively (and feedback mechanisms
to correct those that are ineffective);
• Surveillance and communications systems identifying problems;
EFFECTIVENESS OF AGENCIES Page 16