Evaluating Alternative Operations Strategies to Improve Travel Time ...

SHRP 2 L11: Final Report
The Washington State Department of Transportation (WSDOT) is using high-tech message signs
that deliver real-time traffic information to drivers and adjusted speed limits based on traffic
conditions. Using real-time traffic speed and volume data gathered from pavement sensors,
WSDOT has deployed 97 electronic overhead signs stationed every half-mile along I-5.
Depending on traffic conditions, drivers will see variable speed limits, lane status alerts, and realtime
information about traffic incidents, backups, and alternate routes. In addition, the signs
provide advance notice of lane merges and closures, allowing drivers to change lanes ahead of
time or exit the highway to avoid traffic congestion. (25)
The future of technology integration will not only provide the benefit of combining well-known
ITS strategies, but will also provide resources to support the on-demand urban mobility concept
with the emergence of urban facilities schemes such as car-sharing and bike-sharing. Alternative
market models involving small electric cars, scooters, and electric bikes - all cooperatively owned
and working together - will drastically reduce congestion and improve day-to-day mobility. Thus,
ITS will, of necessity, be more strategic and integrated. It will better demonstrate, through
performance metrics and evaluation, the return on investment. (19) We will see the continued
evolution and integration of previously separate information and safety systems. The establishment
of more strategic approaches and the good use of performance measurements will be critical for
evaluating the efficiency of integrated strategies.
Field tests have been conducted to integrate the Utah Highway Patrol (UHP), the Utah Department
of Transportation (UDOT), Salt Lake City Fire and Police Departments, the Utah Transit
Authority (UTA), and the Valley Emergency Communications Center (VECC) information
systems to enable the real-time exchange of incident data. These tests have revealed the
importance of involving agency IT staff early in the development of the integrated system and the
importance of developing close working relationships among the agencies involved in this effort.
(22)
Another important aspect of integration comes when different transportation modes compete for
the same space on the roadway network. The future of transportation will rely on integrated
systems working harmoniously at the same and different surface levels. For example, passenger
vehicles and transit will have a complementary effort in such way that public transportation will
move people and goods in long urbanized commutes while shared vehicles will help people to
reach their final destination. Modes at different levels such as subways, buses and airplanes will
have synchronized and integrated departure/arrival times - optimizing network usage.
The integration of systems also goes beyond transportation applications. For example, health
conditions will be monitored by vehicles in the future. Breakdown points and specific locations
which may be a threat to health (e.g., heart attacks) can be mapped and linked to congestion
patterns. A better understanding of the correlation of traffic and human factors will be achieved.
(26)
Table 6.14 summarizes additional strategies related to integration/cooperation that will
significantly impact travel time reliability in the next 20 years.
OPERATIONS STRATEGIES AND TREATMENTS TO IMPROVE TRAVEL-TIME RELIABILITY Page 95