3B.1 Use of Connected Vehicle Data in Road Weather Management Applications

Tuesday, 8 January 2013: 8:30 AM
Room 11AB (Austin Convention Center)
Paul Pisano, FHWA, Washington, DC; and C. Hill

Weather has a significant impact on the operations of the nation's roadway system year round. Rain reduces pavement friction. Winter weather can leave pavements snow-covered or icy. Fog, smoke, blowing dust, heavy precipitation, and vehicle spray can restrict visibility. Flooding, snow accumulation, and wind-blown debris can cause lane obstructions.

Weather events may prompt travelers to change departure times, cancel trips, choose an alternate route, or select a different mode. Slick pavements, low visibility, and lane obstructions lead to driving at lower speeds or with increased following distances. These changes in driver behavior can impact the operation of signalized roadways, where traffic signals are timed for clear, dry conditions, through reduced traffic throughputs, increased delays, and increased travel times. Travel reliability for motorists and commercial vehicle operators is affected by a variety of weather conditions. Weather also impacts the operational effectiveness and productivity of traffic management agencies and road maintenance agencies through increased costs and lost time.

It is, therefore, an important responsibility of traffic managers and maintenance personnel to implement operational strategies that optimize system performance by mitigating the effects of weather on the roadways. The operational approaches used by these personnel dictate their needs for weather and road condition information. Accurate, timely, route-specific weather information, allows traffic and maintenance managers to better operate and maintain roads under adverse conditions.

Connected vehicle technologies hold the promise to transform road-weather management. Road weather connected vehicle applications will dramatically expand the amount of data that can be used to assess, forecast, and address the impacts that weather has on roads, vehicles, and travelers; fundamentally changing the manner in which weather-sensitive transportation system management and operations are conducted. The broad availability of road weather data from an immense fleet of mobile sources will vastly improve the ability to detect and forecast road weather and pavement conditions, and will provide the capability to manage road-weather response on specific roadway links.

The US Department of Transportation is providing the national leadership in the connected vehicle program. Connected vehicle research is a multimodal initiative that aims to enable interoperable networked wireless communications among vehicles, the infrastructure, and other wireless devices. Within this program, the Federal Highway Administration (FHWA) through the Road Weather Management Program is developing a concept of operations to define the priorities for connected vehicle-enabled road-weather applications.

Six high-priority connected vehicle road weather applications have been identified and will be described. • Enhanced Maintenance Decision Support System (MDSS) will provide the existing federal prototype MDSS with expanded data acquisition from connected vehicles. Snow plows, other agency fleet vehicles, and other vehicles operated by the general public will provide road-weather connected vehicle data to the Enhanced-MDSS, which will use this data to generate improved plans and recommendations to maintenance personnel. In turn, enhanced treatment plans and recommendations will be provided back to the snow plow operators and drivers of agency maintenance vehicles.

• Information for Maintenance and Fleet Management Systems. The data collected may include powertrain diagnostic information from maintenance and specialty vehicles; the status of vehicle components; the current location of maintenance vehicles and other equipment; and the types and amounts of materials onboard maintenance vehicles, and will be used to automate the inputs to Maintenance and Fleet Management Systems on year-round basis. In addition, desirable synergies can be achieved if selected data relating to winter maintenance activities, such as the location and status of snow plows or the location and availability of deicing chemicals, can be passed to an Enhanced-MDSS to refine the recommended winter weather response plans and treatment strategies.

• Variable Speed Limits for Weather-Responsive Traffic Management. Connected vehicle systems provide opportunities to enhance the operation of VSL systems and dramatically improve work zone safety during severe weather events. Additional road-weather information can be gathered from connected vehicles and used in algorithms to refine the posted speed limits to reflect prevailing weather and road conditions.

• Motorist Advisories and Warnings. Information on segment-specific weather and road conditions is not broadly available, even though surveys suggest that this information is considered to be of significant importance to travelers. Information on deteriorating road and weather conditions on specific roadway segments can be pushed to travelers through a variety of means as alerts and advisories within a few minutes. In combination with observations and forecasts from other sources and with additional processing, medium-term and long-term advisories can also be provided to motorists.

• Information for Freight Carriers. The ability to gather road-weather information from connected vehicles will significantly improve the ability of freight shippers to plan and respond to the impacts of severe weather events and poor road conditions. Information on deteriorating road and weather conditions on specific roadway segments can be pushed to both truck drivers and their dispatchers. In combination with observations and forecasts from other sources and with additional processing, medium to long-term advisories can also be provided to dispatchers to support routing and scheduling decisions. Since these decisions must consider a variety of other factors, such as highway and bridge restrictions, hours-of-service limitations, parking availability, delivery schedules, and, in some instances, the permits held by the vehicle, it is envisioned that the motor carrier firms or their commercial service providers will develop and operate the systems that use the road-weather information generated through this concept.

• Information and Routing Support for Emergency Responders. Emergency responders, including ambulance operators, paramedics, and fire and rescue companies, have a compelling need for the short, medium, and long time horizon road-weather alerts and warnings. Emergency responders have a particular need for information that affects their dispatching and routing decisions. Information on weather-impacted travel routes, especially road or lane closures due to snow, flooding, and wind-blown debris, is particularly important. Low latency road-weather information from connected vehicles for specific roadway segments, together with information from other surface weather observation systems, such as flooding and high winds, will be used to determine response routes, calculate response times, and influence decisions to hand-off an emergency call from one responder to another responder in a different location.

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