Evaluating Alternative Operations Strategies to Improve Travel Time ...

SHRP 2 L11: Final Report
STRATEGIES EFFECTIVENESS AND AREAS OF APPLICATION
The references listed in Appendix F note the literature reviewed in order to quantify the benefits of
each strategy and treatment. No quantitative benefits related to travel-time reliability were
identified in the reviewed documents. However, other measures such as travel-time savings,
improved safety, and increased capacity were quantified. It is assumed that these improvements
have a direct relationship with travel-time reliability. Thus, the strategies/treatments listed in this
section were ranked based on the following general levels of delay reduction:
1. Delay Reduction of up to 50%
2. Delay Reduction of up to 20%
3. Delay Reduction of up to 10%
4. Other Improvements such as safety, capacity, etc.
5. Unknown benefits to date
Table 6.7 through Tables 6.11 present the strategies that fall into each one of the five levels noted
above. In addition, the overall cost ranges for implementing the strategies/treatments are also
provided. An effectiveness rank that considers both the key quantitative benefits of the treatment
(1-5) and its overall cost range (A, B, C, etc.) is also provided for each strategy/treatment.
As shown in Table 6.7 , the treatments with the greatest delay-reduction potential include: National
Traffic and Road Closure Information, Service Patrols, On-Scene Incident and Work Zone
Management, Transportation Management Centers, and Traffic Adaptive Signal Control. These
treatments have been proven to reduce traffic delays by up to 50%. Although these treatments have
a high potential for reducing delay, the costs associated with them are relatively high when
compared with the strategies and treatments in the other four categories.
An important aspect of these treatments is the need for inter-agency cooperation. For example,
National Traffic and Road Closure Information may have to obtain data from weather-related
agencies in order to make it available to the roadway users. In the same fashion, TMCs may have
to be interconnected with emergency responders and law-enforcement authorities in order to
quickly address any roadway disruptions. Additionally, the intent of these treatments is to cover
large portion of roadway networks to benefit roadways across multiple jurisdictions. The following
sections provide a brief overview of the application of the strategies that fall within the category of
reducing delay by up to 50%.
National Traffic and Road Closure Information
The context in which this treatment would apply varies depending upon whether motorists use it
on a national basis when they are seeking information on real-time delay conditions and causes
(i.e., weather, work zone, etc.) that may be encountered on a particular roadway. This information
is made available for pre-trip planning purposes through the FHWA National Traffic and Road
Closure information website (http://www.fhwa.dot.gov/trafficinfo), which also contains links to a
collection of local websites with similar information by state. Thus, the affected area is larger than
the area that would be affected by other treatments and would apply mostly to urban and suburban
areas where large volumes of traffic would benefit from this type of information. The treatment
could apply to facilities operated with or without tolls, and would more likely involve the
dissemination of traffic and road-closure information related to freeway or major arterial facility
types. In addition, the treatment provides information to motorists about both recurring and nonrecurring
congestion conditions (e.g., road closures).
OPERATIONS STRATEGIES AND TREATMENTS TO IMPROVE TRAVEL-TIME RELIABILITY Page 78