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21st Century Operations Using 21st Century Technologies
Table of Contents

2017 Road Weather Management Performance Measures Update

Appendix B. Findings by Measure

ROAD WEATHER MANAGEMENT PROGRAM PERFORMANCE AND RESULTS

Objective 1: Build and sustain relationships with multi-disciplinary partners to expand Road Weather Management deployments.

Table 23. Summary of objective #1 performance measures.
PM #1: Number of agencies participating in road weather Research and Development R&D projects
  • Eighteen (18) State DOTs are currently participating in the Pathfinder Project, including 14 new States.
  • Nine (9) public agencies have participated in the development and use of the RWMP Capability Maturity Framework.
  • Twenty-four (24) State DOTs have participated in the IMO program, a significant increase from the previous period.
  • Twenty-one (21) State DOTs have participated in weather data environment research activities.
  • Four (4) State DOTs have been involved in WRTM implementation support activities. (Again decrease)
  • There is no data on how many State DOTs have been involved in V2I implementation activities or how many are using the IMRCP tool.
  • All in all, forty-one (41) States are conducting at least one activity as compared to only twenty-seven (27) in the prior period.
PM #2: Number of agencies participating in, and benefiting from, road weather management stakeholder meetings/workshops
  • The number of State DOTs attending the annual RWMP meetings has increased from the low of 2014, with approximately half of the States attending the RWMP meetings in 2015 (27) and 2016 (24).
  • The WRTM meeting in 2015 attracted twenty-three (23) State DOTs.
  • The EDC-4 Summits held in 2016 were well-attended, with 48 States participating along with the District of Columbia and the U.S. Virgin Islands.
DOT – department of transportation, IMO – Integrated Mobile Observations, PM – performance measure, R&D – research and development, RWMP – Road Weather Management Program, V2I – vehicle-to-infrastructure, WRTM – weather responsive traffic management

Objective 2: Ensure road weather management investments improve highway performance.

Table 24. Summary of objective #2 performance measures.
PM #3: Number of agencies that collect and report road weather-related performance measures to the public
  • Among the State DOTs surveyed, 22 DOTs reported regularly collecting and reporting some form of road weather performance measures. Thirteen States reported they did not collect and report road weather performance measures, and four respondents were uncertain.
  • Sixteen (16) State DOTs reported the use of a winter severity index to compare performance across events or years.
PM #4: Number of agencies that have a process for evaluating the return on investment or net benefit of their road weather management investments
  • Nine (9) States that have a process in place to evaluate ROI or the net benefits of road weather management investments. This is almost twice the number of States that had such a process in 2015 (5).
  • A 2014 Transportation Research Board research paper compared winter crash data on roadway segments in Idaho before and after deployment of RWIS sites and calculated a benefit-cost ratio of 22, easily justifying the investment.
PM #5: Reductions in agency costs of winter weather-related maintenance and operations activities
  • While local governments have seen a reduction in expenditures for snow and ice removal between 2012 and 2013 (the latest period of data available), State government expenditures have risen in the corresponding time period – resulting in a total expenditure increase of about 13%. This slight increase in expenditure is a shift in direction from the previous decline between 2011 and 2012.
  • The above observations speak to the natural, unpredictable variation in weather and road weather conditions in the short run. Virginia and Pennsylvania experienced the largest increases between 2012 and 2013, spending an additional $80 million and $92 million on winter operations and maintenance, respectively.
  • A 2016 case study in Idaho demonstrated that equipping electronic spreader control systems on snowplow trucks and installing RWIS sites throughout the State helped lower the State's winter maintenance costs by 29 percent over three years; in fact, between 2013 and 2014, Idaho's winter maintenance expenditures were reduced by nearly $2 million.
PM #6: Reduction in number and types of fatalities and crashes attributed to adverse weather nationally
  • The percentage of fatal crashes that occur during inclement weather held steady at 10% in 2014 and 2015.
  • The 10-year average for 2005-2014 shows almost no change in the percentage of weather- related crashes due to adverse road conditions compared to 2002-2012.
  • A 2016 case study on Michigan's weather responsive traveler information system Wx-INFO shows mixed results, with traffic incident rates decreasing in two regions, increasing in two regions, and staying constant in two regions.
PM #7: Reduction in the extent of capacity losses and delays due to fog, snow, and ice events including freight
  • Two case studies have been published since 2015. As a result of Michigan's Wx-INFO system, user delays during National Weather Service advisory and warning alerts decreased between 25 and 67% statewide; in Utah, a survey of motorist behavior during a winter storm event showed that 62% of respondents changed their schedule, 26% changed their route, and 13% decided not to travel based on information provided as a result of the Pathfinder initiative.
PM #8: Increase in travel time reliability or decrease in variability due to road weather management strategies during adverse weather scenarios
  • While still few agencies track reliability measures, more research has been conducted since the prior reporting period in improving travel reliability. As an example, the Mountain- Plains consortium – sponsored by the U.S. DOT – developed a new methodology for incorporating travel times calculated from intelligent transportation system technology into Wyoming's weather condition reporting system.
PM #9: Reduction in the number of tons of salt or chemical usage in the U.S. normalized by Winter Severity Index
  • There was a 20% increase in the amount of salt used for de-icing between 2013 and 2014.
  • Iowa reported that since the State began using a Salt Dashboard, the amount of salt used statewide has been "consistently, and often significantly" below the target. This has contributed to savings of more than $2.7 million annually since 2012.
  • Maryland has reduced its salt usage by 40% over the past three winters through its Statewide Salt Management Plan.
  • Maine's WSI factors historical snowfall data, daily snowfall amounts, ambient temperature, and liquid precipitation; the State views the WSI as a helpful tool to evaluate the effectiveness of winter maintenance equipment, crews, and methods of fighting snow.
DOT – department of transportation, PM – performance measure, R&D – research and development, ROI – return on investment, RWIS – Road Weather Information Systems, WSI – winter severity index

Objective 3: Transportation, weather, and research communities use and rely upon fixed and mobile road weather observations.

Table 25. Summary of objective #3 performance measures.
PM #10: Number of State departments of transportation that are participants in the Meteorological Assimilation Data Ingest System program
  • Ten (10) new States have joined the MADIS program, bringing the total number of States to 21. One state has left the program.
PM #11: Number of State departments of transportation that subscribe to road weather products and services
  • There has been a slight increase in the use of agency sensors (RWIS probes), private weather service providers, and information from the public (including through social media).
  • IMO sensors are now used by over half of the responding States.
  • There are fewer States using National Weather Service and Federal Aviation Administration products, the MADIS system, and agency field personnel for their weather and road weather information. Four (4) States now subscribe to USGS earthquake alerts versus zero from the previous period.
PM #12: Number of State departments of transportation collecting mobile observations of road weather data from appropriate vehicle fleets
  • Overall, twenty-three (23) States, representing more than 50 percent of States surveyed, collect real-time field data from maintenance vehicles. This is an increase from 20 States in the 2015 survey.
  • Collecting plow status and material usage is most common, with thirteen (13) States reporting that they collect more than 50% of their data from maintenance vehicles.
  • Compared to the 2015 survey, there was an overall increase in the number of States reporting that they collect at least 25% of their real-time field data from plow status and material usage, atmospheric weather data (e.g. air temperature, relative humidity), and road weather conditions data (e.g. pavement temperature).
PM #13: Number of State departments of transportation reporting the use of environmental sensor station in operations and maintenance activities
  • In the State DOT survey, the respondents reported a total of 2,464 ESS, which continues the slight decrease seen in the previous update.
  • The majority of respondents use ESS data to provide current conditions to traveler information systems, to support decision-making, and as input to segment-level forecasts. However, while 70% of State DOTs use ESS data for traveler information systems, only 73% report using this data for decision-making, which is down from 95% in the previous period.
  • A positive change can be seen in the increase in the percentage of State DOTs that use ESS data to provide current road conditions to traveler information systems – from 60% in the 2015 survey to 70% in the 2017 survey.
ASOS – Automated Surface Observing System, AWOS – Automated Weather Observing System , DOT – department of transportation, ESS – environmental sensor station, IMO – Integrated Mobile Observations, MADIS – Meteorological Assimilation Data Ingest System, PM – performance measure, RWIS – Road Weather Information Systems

Objective 4: Advance the state of the art for mobile sensing and integrating vehicle data into road weather applications.

Table 26. Summary of objective #4 performance measure.
PM #14: Number of/percentage of responding agencies using mobile data-based applications in road weather management
  • Seven (7) States have developed applications or tools to use data generated by vehicle-to- infrastructure or infrastructure-to-vehicle connectivity. A further seventeen (17) States are considering developing such tools.
PM – performance measure

Objective 5: Advance the state of the practice by promoting tailored management strategies for different regions.

Table 27. Summary of objective #5 performance measures.
PM #15: Number of States disseminating weather advisory and other road weather information to travelers
  • There is a significant increase in the use of dynamic messaging signs to show atmospheric weather and road condition information.
  • More agencies are using social media or mobile applications to disseminate information to travelers, as the use of these portals has increased much more than agency-hosted websites or 511 portals.
  • The use of highway advisory radio has dropped – only half as many States reported statewide dissemination of information over highway advisory radio compared to the previous period.
PM #16: Number of agencies using control and treatment strategies during weather events
  • Traffic incident management continues to be the most widely deployed strategy, with 85% reporting partial or statewide deployment.
  • Loan/road closures and traffic diversions are much less common, showing an almost 30% decrease from the previous period. Temporary vehicle restrictions are also on the decline, as are variable speed limits.
  • Ramp meters are being used by 30% of the respondents, up from the previous period.
PM #17: Number of agencies that have participated in or conducted road weather management capability maturity assessment exercises
  • Ten (10) States have conducted the capability maturity assessment workshops, and one more State has indicated interest.
  • Since the framework was recently developed in 2014, there was no participation to report in the previous period. It is promising that already 10 States, spanning a diverse range of climates, have participated in the in-person workshops in a short amount of time (2015- 2017).
PM #18: Number of agencies that coordinate with their local forecast offices for road weather management and operations
  • Almost all respondents (98%) reported at least some coordination with the National Weather Service (NWS) local forecast office, with 55% saying they routinely coordinate and have access to meteorological expertise. This represents a large increase from 2015, where one- third of the respondents were just starting to work with the NWS.
DOT – department of transportation, HAR – Highway Advisory Radio, NWS – National Weather Service, PM – performance measure, RWM – road weather management, RWMP – road weather management program

Objective 6: Weather-related decision support technologies are integrated into traffic operations and maintenance procedures.

Table 28. Summary of objective # 6 performance measures.
PM #19: Number of agencies adopting maintenance decision support systems technologies and methods
  • The percentage of State DOTs with MDSS deployments, whether statewide or partial, has decreased.
  • There is a corresponding increase in the number of States saying that they do not need an MDSS, whereas the percentage of States saying they need one but do not have one has remained steady. This could suggest that those States that have tried using an MDSS have not found it useful, but that there is a perceived need for such a system.
  • In 2016, FHWA's Road Weather Management Program partnered with the South Dakota DOT to develop and implement a weather responsive traffic management (WRTM) strategy. 24-hour road condition forecasts transfer directly from South Dakota's Maintenance Decision Support System (MDSS) and to their traveler information systems as possible future "threats" when road conditions might deteriorate due to unsafe situations.
PM #20: Number of agencies using other weather-related decision-support tools
  • Respondents indicate an overall decrease in the use of weather-related decision support tools for road weather management, and a few States (12.5 percent) reported not using any tools.
  • Providing traveler information remains the most-used tool, followed by coordination with other agencies, support of non-winter maintenance, traffic control and management, and seasonal load restrictions.
PM #21: Number of agencies reporting use of appropriate analysis tools to factor weather impacts and strategies
  • Ninety five (95) percent of the respondents either did not use or were not aware of whether their agency used weather-responsive analysis tools and models, which is a substantial increase from the last update.
  • Of those who are using such tools, three (3) States are using sketch-planning analysis tools, and one State is using travel demand analysis and traffic signal optimization tools.
  • A 2016 Transportation Research Board study, speed and visibility data were analyzed at several locations along I-64 and I-77 in Virginia, where fog often developed. The research aimed to understand motorists' existing speed choices during low visibility. The models revealed that there is a significant differential between observed speeds and the desired safe speed.
DOT – department of transportation, MDSS – maintenance decision support systems, PM – performance measure

Objective 7: Advance the state of the practice by raising road weather capabilities and awareness across the transportation and weather communities.

Table 29. Summary of objective #7 performance measures.
PM #22: Number of agencies and attendees who have taken any of the training courses and workshops sponsored by the Road Weather Management Program
  • There has been a decline in the number of State agencies participating in courses offered by the Consortium for ITS Training and Education (CITE), but this is expected since the number of RWM practitioners in transportation agencies remains fairly constant.
PM #23: Number of agencies and participants in road weather management webinars led by the Road Weather Management Program
  • The number of agencies participating in RWMP Road Weather Regional Roundtables (webinars) is increasing.
PM #24: Number of meetings, site visits, or venues where road weather management presentations/briefings were made
  • In the 2015-2017 timeframe, RWMP was represented by program staff or support contractors at more than 20 conferences, meetings, peer exchanges, etc.
PM #25: Number of hits/visits to RWMP website
  • None available.
CITE – Consortium for ITS Training and Education, DOT – department of transportation, PM – performance measure, RWMP – road weather management program

Objective 8: Operations community is engaged with climate change and sustainability communities.

Table 30. Summary of objective #8 performance measures.
PM #26: Number of public agencies meeting sustainability criteria related to road weather management
  • Fewer DOTs than in the previous period reported developing and implementing sustainability criteria related to road weather management as identified by Infrastructure Voluntary Evaluation Sustainability Tool (INVEST).
PM #27: Number of agencies conducting vulnerability/risk assessments, developing/ implementing resiliency plans or adaptation plans, for their road weather management infrastructure and processes to respond to climate change and extreme weather
  • The results support this is an emerging area of practice.
  • Half of all respondents have developed practices for responding to extreme weather, and approximately 20% reported conducting vulnerability/risk assessments, developing resiliency plans, and participating in State DOT resiliency adaptation planning activities.
  • Thirty-seven (37) percent expressed being uncertain about their State's activities related to climate change and extreme weather.
DOT – department of transportation, INVEST – Infrastructure Voluntary Evaluation Sustainability Tool, PM – performance measure
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