Evaluating Alternative Operations Strategies to Improve Travel Time ...

SHRP 2 L11: Final Report
Electronic Toll Collection (ETC)
ETC treatments have a limited application area that includes tolled freeway facilities. The high
installation costs of this treatment are another limiting factor. Thus, they are usually confined to
facilities in larger urban areas that serve regional travel needs. ETCs are also a treatment that can
be applied in areas where the objective is to reduce recurring congestion by expediting transactions
at toll booths via tag readers, license plate recognition, cell phones, or GPS units. It should be
noted that as costs decrease for ITS technologies in the future, the deployment of ETCs may
become more widespread.
Table 6.8 shows the second most-effective group of strategies and treatments found in the
literature review. Accordingly, the supporting references are also shown in Table 6.8. The
treatments included in this group include: CCTV, Pre-trip information Road Weather Information
Systems, Dynamic Message Signs, Geometric Design Treatments, Signal Retiming, AVL, Ramp
Metering, Congestion Pricing, and Managed Lanes. Interestingly, these treatments have lower
costs when compared to the Level 1 treatments A common characteristic of these treatments is that
they address local congestion sources and their benefits may not been seen in other parts of the
roadway network. The context in which each of the treatments associated with Table 6.8 could be
applied was also considered as described below.
Remote Verification (CCTV)
This treatment has a localized use associated with its application given the relatively limited
viewing areas around CCTV devices. As a result, a series of CCTV cameras are typically deployed
to widen the coverage area along a facility. The setting in which this treatment can be applied is
varied and includes the monitoring of urban area networks (e.g., CBDs), suburban arterials, and
freeways. The lack of available communication infrastructure is a common controlling factor for
the application of this treatment in rural areas and along local roads. This treatment type can also
be applied in areas with both recurring and non-recurring congestion and can be used to monitor
the status of either (typically via a TMC).
Pre-trip information by 511, web sites, subscription alerts, radio
This treatment type provides pre-trip information to motorists through the internet, television or
radio in close-to-real-time. The source of this information is typically CCTV cameras and eyewitness
traffic reports which is then relayed to the public through a variety of media outlets. This
treatment can be applied on a local or regional basis for any area (urban, suburban, rural) and
facility type. The treatment provides valuable information during both recurring and non-recurring
congestion conditions that can be used by motorists when planning a trip.
Road Weather Information Systems (RWIS)
This treatment has application to the many areas throughout the country that experience weatherrelated
disruptive impacts on the transportation system. The Road Weather Information Systems
can be installed in all area and facility types where a significant threat to the operation is posed by
weather. Additionally, this treatment can be interconnected with local and regional TMCs.
Dynamic Message Signs (DMS)
DMS plays an important role on travel-time reliability since it is one of the main sources of traveltime
reliability information for en-route roadway users. Permanently-mounted Dynamic Message
Signs that provide real-time traffic information such as travel times, incidents, weather,
construction, safety, and special events are mostly applied to freeways and arterials, given the need
for good communication throughout an area. The application of DMSs is more common in urban
areas, but they can also be found in suburban and rural areas. Additionally, they are used to
disseminate information where both recurring and non-recurring congestion conditions exist.
OPERATIONS STRATEGIES AND TREATMENTS TO IMPROVE TRAVEL-TIME RELIABILITY Page 81