Evaluating Alternative Operations Strategies to Improve Travel Time ...

SHRP 2 L11: Final Report
Table 6.10 Level 4 Strategies (Other Improvements – Safety, Throughput)
Category Strategy Treatments
2.Information
Collection
and
Dissemination
5.
Infrastructure
Improvements
and Demand
Optimization
2.1.Surveillance
and Detection
2.2.Probe
Vehicles and
Point Detection
5.1.Geometric
Design
Treatments
5.5.Variable
Speed Limits
Driver
Qualification
Automated
Enforcement
GPS, Video
Detection,
Microwave
Radar,
Bluetooth
MAC Readers
Geometric
Improvements
(Interchange,
Ramp,
Intersections,
Narrow
Lanes,
Temporary
Shoulder
Use)
Variable
Speed Limits
(VSL)
Overall Cost Range*: Low - 200K but < 1 million
High - >1 million
Application
to Sources
of
Congestion
Traffic
Incidents
Traffic
Incidents,
Bottlenecks
Traffic
Control
Devices
Physical
Bottlenecks,
Traffic
Incidents
Physical
Bottlenecks,
Special
Events
Key
Quantitative
Benefits
Reduce nonrecurring
congestion by
reducing
accidents.
Reduces
travel time
and improves
safety.
No direct
benefit to
reducing
congestion
Geometric
improvements
revealed
increased
overall
capacity by
7% to 22%.
Increases
throughput by
3% to 5%.
Overall
Cost
Range*
Low 4-A
Variable
(High if
done by
agencies,
Low if done
by
contractors)
Effectiveness-
Cost Rank
4-D
Low 4-A
Medium 4-C
Low-
Medium
4-B
The last group of strategies and treatments (identified as Level 5) is shown in Table 6.11. These
strategies and treatments are not necessarily less effective than the previous groups, but their
benefits were not quantified in the literature. Such treatments include: Vehicle Infrastructure
Integration, Access Management, Changeable Lane Assignments, Integrated Multimodal
Corridors, and Travel Alternatives. One of the reasons why information regarding benefits was not
found is that some of these treatments are relatively new and their potential effectiveness is under
evaluation. Despite this, strategies such as Access Management and Lane Treatments are welldocumented
in terms of standards and implementation, but there is a lack of information regarding
their performance. The context in which each of the treatments associated with Table 6.11 could
be applied was also considered as described in the section below.
Vehicle Infrastructure Integration (VII) is a treatment currently undergoing testing in several
locations such as California and Michigan. The treatment provides full communication between
vehicle and infrastructure by combining technologies such as advanced wireless communications,
on-board computer processing, advanced vehicle-sensors, GPS navigation, smart infrastructure,
and others, to provide the ability for vehicles to identify threats and hazards on the roadway and
communicate this information over wireless networks to give drivers alerts and warnings. As such,
OPERATIONS STRATEGIES AND TREATMENTS TO IMPROVE TRAVEL-TIME RELIABILITY Page 87