Ops Council Mtg TRB

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Chicago Metro APWA Snow Ice Control Road
Weather Information Systems October 20, 2004
Ray Murphy Federal Highway
Administration
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Road Weather Information Systems
Presentation Overview

• Weather Impact
• Introduction (terms, definitions)
• RWIS
• Applications Resources

Chicago Metro APWA Snow Ice Control
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Weather
Affects transportation outcomes of

• Safety
• Efficiency
• Cost

Weather Impact
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Impacts of Weather on Highway Safety
70 vehicle crash on I-5 in heavy rain. Several
Injured 1/30/04
38 vehicle crash on I-43 in fog. 10 Dead. 2/11/02
130 vehicle crash on I-95 in snow. 2 Dead 2/22/01
194 vehicle crash on I-710 in fog. 41
Injured. 11/04/02
60 vehicle crash on I-94 in snow. 1 Dead. 2/7/03
73 vehicle crash on I-68 in fog. 2 Dead. 100
Injured 5/24/03
66 vehicle crash on I-15 in fog. 24 Injured.
4/01/04
Weather Impact
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Every Year in the United States

• Nearly 7,000 fatal highway crashes and over
  450,000 injury crashes occur annually
• 2.5 billion is spent annually for snow and ice
  control
• About 5 billion is spent on weather related
  infrastructure damage
• Billions of dollars are lost in delay and
  disruption to trips and production

because of weather
Weather Impact
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Winter Maintenance

• A 2.5 billion/year activity of state and local
  highway authorities
• Involves
• stocking of materials
• purchase of equipment
• scheduling of crews
• dispatching for pretreatment, snow/ice removal
  and salting/sanding
• Maintenance operators use weather information of
  several kinds and scales -- from long range
  forecasts to data from roadside sensors

Weather Impact
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Impacts of Weather on Mobility
How is the congestion pie sliced?
Travel delay can increase by 11 to 50 depending
on weather severity
Incidents (crashes, disabled vehicles)
Weather (snow, ice, fog)
Other recurring
Work Zones
Other non-recurring e.g. special events
Poor signal timing
Weather Impact
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list of common acronyms CDU
Control Data Unit CPU Central
Processing Unit. ESS Environmental
Sensor Station ITS Intelligent
Transportation Systems NTCIP National
Transportation

Communications for ITS Protocols NWS
National Weather Service RAS Remote
Access Server. RPU Remote Processing
Unit. RWIS Roadway Weather Information
System.
Synoptic Weather Forecast 12 hrs
Meso-Weather Forecast 1-12 hrs
Observations and Reports 0-1 hrs
Introduction (terms definitions)
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Weather models

• over a three-dimensional domain forward in time

• complex physics and mathematical frameworks

Navier-Stokes equations

• models are global, nationwide or local
  (mesoscale) in scope

• atmospheric structure and the lower boundary of
  the atmosphere (land and water)

Road-weather models

• algorithmic solutions to site-specific road
  conditions

• inputs provided by the 'weather models'

• accumulated historical weather for a given
  locale, typically an RWIS ESS

Introduction (terms definitions)
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Environmental Sensor Station

• one or more sensors

• atmospheric, pavement, soil and/or water level
  conditions

• data collected in the field is stored on site in
  a Remote Processing Unit (RPU) located in a
  cabinet

• RPU transmits environmental data to a central
  location via a communication system

Environmental data may be used to activate
roadway devices, provide decision support to
managers, furnish the public with traveler
information, and enhance forecasts.
Introduction (terms definitions)
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Types of Data Collected and Reported
Introduction
4-7
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Atmospheric Data Definitions
Introduction (terms definitions)
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Introduction (terms definitions)
Atmospheric Data Definitions continued
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Introduction (terms definitions)
Atmospheric Data Definitions continued
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Atmospheric Data Definitions continued
Introduction (terms definitions)
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What are Road Weather Information Systems (RWIS)?
The use of weather sensors placed strategically
along a roadway or on vehicles to provide near
real-time data of road weather and pavement
temperature conditions, combined with tailored
weather and pavement condition information, to
provide road maintenance personal and the general
public with a decision tool for snow and ice
control and route planning.
RWIS
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Components of RWIS

• Environmental Sensor Stations
• Processing Systems
• Forecasts and Models
• Dissemination

RWIS
4-5
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RWIS from the 1970s to today

• 1970s Devices first tested on bridges
• 1980s Then introduced to the general highway
  environment
• Today Now refers to a whole spectrum of data
  resources

RWIS
4-4
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RWIS Improvements

• New sensor technologies
• New sensor siting guidelines
• New NTCIP Environmental Sensor Station Standards
• Improved NWS feeds and data sharing
• Better road condition models
• Open systems development for information
  exchange
• Data fusion of multiple data sources and scales

RWIS
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Typical WEATHER STATION COMPONENTS
RWIS
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RWIS SENSORS- ATMOSPHERIC -

• Wind speed/direction (mph)
• Temperature/relative humidity
• Air temperature in degrees F
• Relative humidity in percent
• Dew point (degrees F) calculated from
  temperature, relative humidity

RWIS
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RWIS SENSORS- ATMOSPHERIC continued -

• Precipitation (yes/no)
• Weather Identifier and VISibility (WIVIS) present
  weather
• Type of precipitation (rain, snow, drizzle)
• Precipitation intensity
• Visibility in miles or increments if less than
  one mile

RWIS
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Weather Identifier and VIsibility Sensor (WIVIS)
RWIS
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RWIS SENSORS - PAVEMENT -

• Pavement surface temperature in degrees F
• Surface condition (state of road)
• Dry, wet, dew, frost
• Snow/ice watch/warning
• Chemical factor
• Depth of moisture
• Percentage of ice in solution
• Solution freeze point
• Percent chemical in solution

RWIS
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RWIS SENSORS - PAVEMENT -

• Subsurface temperature probe
• Soil temperature (in degrees F) 18 inches below
  pavement surface
• Some sites also have subprobe at 36 inches

RWIS
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Site Selection

• Correctly choosing the best location

• Power and telecommunication requirements

• common site specific problems to which common
  RWIS sensors are susceptible

• height of the sensor above the ground and
  orientation

• outside the wheel path of vehicles, at a location
  that is known to freeze early

RWIS
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Advanced Roadway Monitor
Complements of WeatherScene
www.mcq-sii.com

• Full Sensor Suite
• Weather (Visibility, Wind, Temp, Pressure,
  Humidity)
• Imagery (Color, BW, IR Thermal)
• Traffic (Vehicle Counts, Speed, and
  Classifications)
• Pavement (Dry, Wet, Icy, Temp)
• Autonomous Operation
• Intelligent Roadside Processing
• Low Power (Solar or AC)
• Flexible Communications (RF, Fiber, Phone,
  Satellite)
• Rugged Construction

Fixed Installation for Virginia DOT
Applications Resources
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Typical InstallationI-40 / Riordan AZ
Complements of WeatherScene
Sensors
Electronics Cabinet Interior
Folding Tower
Electronics Cabinet
Applications Resources
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Sensor Installation
Weather POD
Precipitation
Color Cameras
Traffic
Applications Resources
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SurfaceWatch Non-Contact Pavement Monitor

• Infrared sensors that can remotely detect
  pavement conditions.
• Suite of instruments to detect
• Presence of a water film on pavement
• Pavement temperature
• Concentration of deicing/anti-icing materials in
  water film

Applications Resources
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SurfaceWatchInstallation

• Covers Full Traffic Lane
• Range of 30 45 Ft
• Provides Condition Data
• (Dry, Wet, Ice, Snow,
• Surface
• Sub-Surface Temp)
• No Sensors Installed in
• Roadbed

Pole Mounted Beside or Over Roadbed
INFRARED BEAM
Sensor Height
Subsurface Sensor Mounted 1 Ft Below Grade
Measurement Area On Road Surface
Applications Resources
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SurfaceWatch Applications

• Trigger Warning Signs
• Trigger De-Icing
• Monitor Storm Progress
• Improve Maintenance Deployment

• Bridge Decks
• Mobile Work Zones
• Steep Grades
• Remote Locations

Applications Resources
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RWIS in the Midwest

• Environmental Sensor Stations (ESS) are used to
  observe or measure three types of road weather
  information
• atmospheric data,
• pavement data, and
• water level data.

Applications Resources

• Wisconsin - 61 RWIS stations
• Iowa - 85 RWIS stations
• Illinois - 87 RWIS stations
• Minnesota - 154 RWIS stations,
• Indiana - 24 RWIS stations
• Ohio - 158 RWIS stations

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RWIS network within Illinois

• The Challenge

• Putting the Technology to the Test

• The Benefits

Applications Resources
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Chicago area RWIS sites
Applications Resources
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Ohio DOT Roadway Weather Information System
(RWIS) Expansion
addition of 86 weather stations to the 72 already
in operation, the 158 weather stations provide
coverage of all 88 Ohio counties making it the
largest deployment of RWIS in the U.S.
Applications Resources
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Applications Resources
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Applications Resources
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http//www.ops.fhwa.dot.gov/weather/Publications/R
WIS_brochure.pdf
Applications Resources
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Learn More The U.S. DOTs ITS Standards Program
has information and resources pertaining to NTCIP
ESS available at www.its-standards.net. NTCIP
Document 1204 Object Definitions for
Environmental Sensor Stations (AASHTO, ITE, NEMA)
defines the ESS protocol. This document is
available at www.its-standards.net/Documents/NEMA-
TS3.7.pdf. An Aurora Program report on display
standards, IdeDevices and Data Formats, is
available at www.aurora-program.org
Applications Resources
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Applications Resources
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Examples of state RWIS specifications that cite
the NTCIP standards are available on the Aurora
Program web site at http//www.aurora-program.org/
matrix.cfm Aurora is an international
partnership of public agencies working on RWIS.
http//www.benefitcost.its.dot.gov/ITS/benecost.ns
f/SearchAll?SearchViewQueryRWIS
http//www.ops.fhwa.dot.gov/weather
Applications Resources
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sample RWIS RFP
Applications Resources
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Applications Resources
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Applications Resources
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A successful RWIS program will depend on the
careful coordination of these three essential
areas.
SENSORS

• determine exactly what you need and to what
  accuracy

FORECASTS
OBSERVATIONS

• conduct a site survey to
• determine the optimum site for RWIS installation

• develop a plan for long-term support of the RWIS

MATERIALS
EXPERIENCE
SALT USAGE
CONSTITUENTS
Applications Resources
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Benefits of RWIS
Safety
Economic Vitality
Mobility
Applications Resources
4-11
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Ray Murphy ray.murphy_at_fhwa.dot.gov
The goal the Road Weather Management and
Operations (RWMO) Community of Practice (CoP)
website is to encourage discussions related to
weather-surface transportation issues and
opportunities, to foster and contribute
significantly to the research, development and
implementation of related technologies and
innovative practices. All are welcome to post
comments and updates.
This community is dedicated to the open exchange
of information and knowledge on road-weather
management, operations and research related
information. Please register at the associated
Directory. The Directory provides e-mail
addresses and organizational affiliations of
participants and facilitators.
http//knowledge.fhwa.dot.gov/rwmo