Regional Operations Forum

Road Weather Management

Accelerating solutions for highway safety, renewal, reliability, and capacity

Session Objectives

• Provide high-level awareness of road weather

management

• Develop awareness of principles and elements

associated with modern road weather management

• Understand how to implement elements of road weather

management

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The Road Weather Problem

• Safety:– 1.57± million weather-related crashes/year

• 7,400 fatalities; 690,000 injuries

– 24% of all crashes occurred on slick pavement or under adverse weather

• Mobility: 15% of delay caused by bad weather

• Productivity: Weather-related delay adds $3.4 billion to freight costs annually

• Environment: Chemicals effect watersheds, air quality and infrastructure

3

Types of Weather

• Winter weather

– Snow, especially first snow

– Blowing and drifting snow

– Freezing rain

• Rain

– Especially heavy rain or first rain

• Limited visibility

– Fog or dust/sand storms

• Frost

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Weather Effects on Traffic

Operations

• Reduced Visibility

• Reduced Roadway Friction

• Reduced Roadway Capacity

• Damaged Infrastructure

• Blocked Roadways

• Inundated Roadways and Flooding

• Coastal Evacuation

• Increased Speed Differential

• Increased Driver Stress

5

Weather Data and Information

Sources

• Road Weather Information Systems (RWIS)—Fixed

sensors and mobile sensors

• Weather observing systems

– Automated Surface Observing Systems (ASOS) —

NOAA

– Automated Weather Observing Systems (AWOS) —

FAA

– Both provide the basis for NWS forecasts

• MADIS

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Road Weather Information

System (RWIS)

• Environmental sensor stations

(ESS) to collect data

• A communication system for

data transfer

• Central server to process data

• Dissemination of information to

agencies/motorists

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How is RWIS used?

8

ESS

RWISINFORMATION STAKEHOLDERS NEEDS

CAMERAS

TRAFFIC

NWS

MAINT

NWS

WSP

TMC

511

Michigan RWIS Deployment

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Available Weather Resources

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Meteorological Assimilation Data

Ingest System (MADIS)• Collect, integrate, quality control, and distribute

observations from NOAA and non-NOAA organizations.

• Leverages partnerships with multiple partner agencies to

integrate observations

– Including state departments of transportation

– Provides a finer density, higher frequency

observational database for use by the greater

meteorological community

• MADIS runs operationally in real time in the National

Weather Service (NWS)

• Many states are making RWIS data available to MADIS

12

Weather Forecasts

• All weather observations can improve weather forecasts

– The more information, the better

– National Weather Service

– Private meteorological services

• RWIS performs double duty

– RWIS information is used directly by maintenance

crews, supervisors, and managers

– Information from RWIS feeds and improves weather

forecasts

13

Benefits of Reliable Weather

Forecasts

• Improved resource allocation

– Crews sent to the right places at the right times

– With the right equipment

– With the right treatment material (and the right

amount)

• Effective resource allocation results in safer roads and

reduced costs

A key to effective road weather management is timely

and accurate forecasts and measurements.

14

Pavement Condition Prediction

• Forecasts of pavement temperatures and conditions

• Supporting information for treatment decisions

– When and if to treat

– What type of treatment to use

• Valuable input to maintenance staff for resource

allocation

15

Weather Responsive Traffic

Management (WRTM)

• Three types of WRTM strategies

– Advisory strategies provide information on prevailing

and predicted conditions

• Posting fog warnings on dynamic message signs

• Listing flooded routes on web sites

– Control strategies alter the state of roadway devices

to permit or restrict traffic

• Reducing speed limits with variable speed limit signs

• Modifying traffic signal timing based on pavement conditions

– Treatment strategies supply resources

• Most common treatment strategies are application of sand,

salt, and anti-icing chemicals to pavements

16

Maintenance Decision Support

System (MDSS)

• System to support winter maintenance activities

• Capitalizes on existing road and weather data sources

– Augments data sources where they are weak or

where improved accuracy could significantly improve

the decision-making task

– Fuses data to make an open, integrated, and

understandable presentation of current environmental

and road conditions

• Proactive resource management, equipment

management, cost management for highly variable

winter operations

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18

,000

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MDSS Benefits

• Indiana DOT program benefits

– Statewide implementation 2009

– Saved 228,000 tons of salt = $12M

– Saved 58,000 hours of overtime = $1.4M

• One-stop for winter weather information

• Consistency in tracking/reporting among regional

maintenance groups

• Supports proactive training

• Looking toward mobile data collection capabilities

20

Road Weather Management

Performance Measures

• Will differ on types of weather encountered

• Will differ by agency objectives

• Sample measures

– Regain time

• Time to return to “normal” seasonal conditions

– Coefficient of friction or “grip” factor

– Benefit–Cost

• What weather related performance measures does your

agency use?

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Notable Trends

• Open RWIS architecture

• Noninvasive sensors

• Importance of camera imagery

• Mobile data collection and AVL

• Multistate weather response coordination

• Interest in connected vehicles

• Integration of weather and traffic management (@ TMC)

– Including traveler information

• Emphasis on performance measurement

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Group Discussion

• What weather events do you have to manage?

• What road weather management tools do you use?

• What has been successful?

• What are the gaps you still have?

• What new equipment, systems, or processes are you

developing or exploring?

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Weather Takeaways

• Do you take advantage of all the weather resources

available to you (appropriate to your role)?

• Has your agency looked into mobile weather data

collection?

• Has your agency looked into the MDSS? Does it use it?

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