Evaluating Alternative Operations Strategies to Improve Travel Time ...

SHRP 2 L11: Final Appendices
suburban, rural, and work-zone settings. DMS are becoming more prevalent and are a very
effective way to convey expected travel conditions to travelers (6, 9, and 14).
Vehicle Technologies
3.1 Vehicle Infrastructure Integration
Vehicle Infrastructure Integration (VII) is a new technology concept that will provide full
communication between vehicles and highway infrastructure. It combines technologies such as
advanced wireless communications, on-board computer processing, advanced vehicle-sensors,
GPS navigation, smart infrastructure, and others to help vehicles identify threats and hazards on
the roadway and communicate this information over wireless networks to give drivers alerts and
warnings. The following are some informational products:
• Route guidance
• Traffic advisories
• In-vehicle signing
Several states, including California and Michigan, are evaluating ITS technology communication
advances. Such technology is expected to improve travel-time reliability by providing real-time
information to roadway users and agencies about road conditions, traffic, weather, and detours (7,
15).
3.2 Driver Assistance Products
Driver assistance systems can help make driving safer by recognizing potentially dangerous
situations. Such systems are typically based on sensors and cameras connected to a central vehicle
information system that provides warnings to the driver or directly intervenes in the driving
process by braking or accelerating. These systems can be classified as side assist, front assist,
brake assist, blind corner monitor, and parking and rear assist.
Advanced Crash Avoidance Technologies. ITS can help to eliminate a large number of crashes
and reduce the severity of crashes that do occur. Unprecedented levels of safety, mobility and
efficiency will be made possible through the development, integration, and deployment of a new
generation of in-vehicle electronics, vehicle and infrastructure automation, and selective automated
enforcement, including determining whether drivers are fit to drive. The following is a list of
active safety technology:
• Forward and rear collision avoidance
• Intersection collision avoidance
• Lane departure prevention
All of these aid drivers and allow vehicles to perform better and safer. Performance of in-vehicle
systems can be further improved by connecting them with the infrastructure that provides
information on road and traffic conditions. In addition, infrastructure-based warning and guidance
technology can help improve safety for all vehicles, even those that are not specially equipped.
The following is a list of other driver assistance products:
• Curve speed warning
• Adaptive cruise control
• Self-aiming headlights
• Vision enhancement systems (night or fog assistance)
ADDITIONAL DESCRIPTION AND QUANTITATIVE BENEFITS OF TRAVEL-TIME RELIABILITY STRATEGIES Page F-5