Chapter 1. Introduction
The Federal Highway Administration’s (FHWA) Road Weather Management Program (RWMP) has been leading national efforts to mitigate the impacts of weather on roadway infrastructure and operations for many years. The RWMP has sponsored many strategic and developmental initiatives, providing frameworks for data gathering, quality checking, operational response, decision support, information dissemination, performance measurement, technology transfer, and interagency cooperation.
Among these RWMP initiatives, the development of weather-responsive traffic management (WRTM) focuses on actionable strategies for system management and operations. It is potentially the most impactful of RWMP initiatives, since it directly affects the driving public and agency responses to roadway conditions. Although the potential impacts of using WRTM strategies can be valuable, the strategies can be challenging to implement effectively. They require sufficient information on traffic and weather conditions; development of appropriate strategies, infrastructure, and information systems to support implementation of those strategies; agency operators supportive and knowledgeable of the strategies; and drivers who are aware and responsive.
Over the years, the RWMP has addressed these challenges in a variety of programs supportive of technology and strategy developments. Condition data gathering has been developed throughout the Clarus, Integrating Mobile Observations (IMO), Meteorological Assimilation Data Ingest System (MADIS), and Weather Data Environment (WxDE) efforts. It is being expanded through the connected vehicle (CV) data standards in anticipation of widespread mobile observation availability. WRTM strategies for dealing with road weather conditions have been explored in projects investigating winter maintenance with plow routing and anti-icing treatment, variable speed limits (VSL) for low-visibility and weather-degraded pavement conditions, and variable message signs (VMS) to inform drivers of imminent road weather conditions. These strategies are then supported by development of infrastructure and systems, such as fixed and mobile sensors for data gathering and for treatment, the Maintenance Decision Support System (MDSS), Pikalert®, and guidance for message sign use in hazardous weather conditions. FHWA has provided operations support though the Every Day Counts (EDC) initiatives (Rounds 4 and 5), Pathfinder initiative, the Road Weather Management Exchange, road weather management stakeholder meetings, and focused WRTM meetings.
Road weather management application analyses and WRTM efforts have also included foundational studies of the effectiveness of technologies and strategies using analysis, modeling, and simulation (AMS) tools. Most studies of operations strategies with AMS tools have looked more generally at the network or corridor responses to active traffic demand management (ATDM) or control strategies to improve mobility. The RWMP has more specifically invested in studies of the benefits of weather-responsive maintenance activities and traffic management. These have included seminal studies of road weather ATDM and CV dynamic mobility applications (DMA), further studies of traffic signal optimization in degraded-weather conditions, and the study of Integrated Modeling for Road Condition Prediction (IMRCP), which brings together weather and traffic prediction in online, near-real-time forecasts.
The remaining challenge is to bring these research elements into an integrated assessment of CV-enabled weather-responsive management strategies (WRMS). Agencies will then be able to use AMS tools to inform operational decisions for their specific sites, strategies, and conditions. The objectives of this study are to:
This report documents the activities and findings of the study.
United States Department of Transportation - Federal Highway Administration