2019 Road Weather Management Performance Measures Update

Executive Summary

The Federal Highway Administration's (FHWA) Road Weather Management Program (RWMP), more than a decade ago, established a set of performance measures to assess its program effectiveness in improving the performance of the transportation system during adverse weather conditions. Since then, assessments of the performance measures have been completed and documented in 2009, 2012, 2015, and 2017. Over the years, the RWMP has aimed to maintain overall consistency in the types of performance measures to allow for a more complete, long-term assessment of a program. However, additional performance measures were added in 2015 to address some gaps due to changes in program objectives and recent advances in road weather management capability and technology. For the 2019 report, two performance measures were removed from the assessment of RWMP objectives as they were deemed to measure outdated or irrelevant road weather management practices. As a result, 25 performance measures are evaluated in this 2019 Road Weather Management Performance Measures Update. This update maintains the same performance measures to assess the RWMP's success in meeting its programmatic objectives:

1. Build and sustain relationships with multidisciplinary partners to expand road weather management deployments.
2. Ensure that road weather management investments improve highway performance.
3. Advance the transportation, weather, and research communities' use of and reliance on fixed and mobile road weather observations.
4. Advance the state of the art for mobile-sensing and integrating vehicle data into road weather applications.
5. Advance the state of the practice by promoting tailored management strategies for different regions.
6. Improve integration of weather-related decision support technologies into traffic operations and maintenance procedures.
7. Advance the state of the practice by raising road weather management capabilities and awareness across the transportation and weather communities.
8. Increase engagement of the operations community with the weather resiliency and sustainability communities.

Assessing performance measures allows the RWMP to evaluate its progress, gather information on the state of the practice and national capabilities in road weather management, and identify any areas that need more focus, support, or outreach. The resulting report presents the progress, successes, and overall vision of the RWMP. It serves as a potential resource and communication product for advancing the importance and widespread implementation of road weather technologies.

Road Weather Management Impacts

This report describes the recent practices and performance measures related to mitigating the mobility, safety, economic, and productivity impacts of adverse weather conditions. The study team found that an increasing number of agencies are collecting and reporting data on road weather performance measures, though many agencies still are determining the best methods for increasing capabilities for road weather management strategies and communicating those benefits to the public. Some examples are: publishing winter maintenance reports, providing online dashboards, calculating a winter severity index, and developing a process for evaluating the return on investment of road weather strategies.

Since the 2017 update, snow and ice removal expenditures have fluctuated based on the weather conditions but notable reductions in salt usage were not observed. Also, not many agencies are currently tracking the impact of road weather management on travel time reliability, but there are some notable practices for reducing delays in inclement weather. The Virginia Department of Transportation (VDOT), for example, implemented a variable speed limit in a corridor with frequent fog events to influence driver behavior. VDOT found that doing so did not significantly delay travel into or out of the corridor.

A primary concern for the RWMP and transportation agencies is reducing roadway fatalities. The rate of fatal crashes during inclement weather has remained relatively constant in the past 8 years.

Application of Road Weather Management Tools and Technologies

The first set of road weather management tools examined pertains to the collection of fixed and mobile road weather observation data, which can be made available in real-time or archived. The number of State Departments of Transportation (DOTs) using such systems since the previous report has remained relatively constant for most tools. However, fewer agencies reported relying on National Weather Service (NWS) products, and more reported relying on public or social media for information. The research team found that agencies increasingly are collecting real-time field data from their maintenance vehicle fleet, primarily for information on snowplow status and material usage.

The percentage of State DOTs using a Maintenance Decision Support System has increased, with more usage reported than the 2017 report. The RWMP encourages State DOTs to utilize road weather management strategies that best fit the local context. Fewer agencies are finding it helpful to provide traveler information to the public, but more are using weather-related decision support tools to support non-winter weather maintenance activities. Still, 83.8% of agencies reported that they did not use or were unaware if they used weather-responsive analysis, modeling, or simulation tools.

The research team also followed up on the 2017 update by tracking the use of vehicle-to-infrastructure or infrastructure-to-vehicle applications and connected vehicle technology. This topic has overwhelming improvements since the last update. Whereas in the previous update just 17% of agencies had developed an application that used real-time data from vehicle fleets, in this update, over 44% of agencies reported having developed an application. An additional 47% reported considering the development of one.

More agencies also reported that they had conducted a vulnerability assessment; developed or implemented a process for responding to extreme weather or a plan for resilient road weather management infrastructure; or participated in State DOT resilience adaptation planning activities.

Road Weather Management Capacity Building

This report contains an evaluation of how the RWMP is providing stakeholders with flexible, accessible learning and growth opportunities through training, technical assistance, and resources. Overall, participation in RWMP stakeholder meetings has been consistent and strong since the last update. The number of agencies participating in RWMP Regional Roundtables (webinars) has increased. A notable development since the last update, the RWMP has been converting the Consortium for Innovative Transportation Education's (CITE's) road weather management courses into a more broadly applicable format to be delivered by the National Highway Institute (NHI).

FHWA has worked with 16 State DOTs to conduct Road Weather Management Capability Maturity Framework (CMF) workshops. These workshops walk the agency through a self-assessment that was developed in 2014 to assess institutional road weather management capabilities and to help identify priority actions for increasing those capabilities.

Partnerships and Stakeholder Collaboration

Because information sharing is fundamental to the implementation and success of road weather management strategies, FHWA and contractor staff frequently collaborate with public and private stakeholders through various activities on behalf of the RWMP. To gauge the effectiveness of these efforts, the RWMP tracks the numbers of State agencies advancing research and development projects, such as Pathfinder, Road Weather Management CMF, Weather Data Environment, and the Integrated Mobile Observations Program. In 2019, all major research and development (R&D) projects observed an increase in participation, and 43 States were involved in at least one project.

The RWMP also supports the National Oceanic and Atmospheric Administration (NOAA) and the National Weather Service (NWS) by encouraging State DOTs to utilize resources like NOAA's Meteorological Assimilation Data Ingest System (MADIS) or the National Weather Service's NWSchat. The research team found that fewer numbers of agencies rely on MADIS, but more agencies routinely coordinate with NWS to assist decision-making related to inclement weather or major events.

Conclusions

The RWMP is at a turning point with close to 15 years of research and development, stakeholder engagement, and accomplishments. Overall, the program's role in enabling improved management of the transportation system during adverse weather is evident in the strong growth in use of tools, programs, and activities by State DOTs. The results from the performance measurement show the sustained interest and growth in Every Day Counts (EDC)-supported strategies. As EDC-4 and EDC-5 ramp down, the question becomes: What are the next steps for the program in terms of supporting the advancement of road weather management practices? The 2019 performance measurement data provides some clues about likely needs and requirements for the program, such as:

• Need for more case studies on material management practices, especially documenting State DOT approaches to optimizing usage of salt.

• Need to re-engage State DOTs on Road Weather Information System (RWIS) data sharing. This update revealed that a smaller number of State DOTs are reporting their contributions to MADIS. The role of RWIS data sharing may re-emerge as a priority, especially with other voluntary data exchanges being developed to support automated driving systems.

• Overall, there is significant growth in the use of data generated from vehicle platforms for road weather maintenance. Maintaining these advancements requires the RWMP to support overall maturity in the use of these systems, including data management practices, application development, and the systems' operations and maintenance.

• A map of survey respondents and analysis of State involvement reveal clear geographical gaps in engagement in the southeastern United States. This may result from the markedly different focus on winter weather-related activities historically by the program as well as the Southeast. Understanding the needs of these States and seeking to engage them more would make the program more broad-based in terms of looking at road weather impacts beyond snow and ice control. The Pathfinder initiative is currently evolving to be more inclusive of non-winter events, such as flooding, tropical storms, and dust storms.