Highway Weather Information Needs & Requirements

Paul Pisano

Road Weather Management Coordinator

Federal Highway Administration

4-Step Process

• Step 1 – Information Needs

• Step 2 – Operational Concept Description

• Step 3 – Preliminary Interface Requirements

• Step 4 – Test & Evaluation

Step 1 – Information Needs

• Focus is on decision makers– first understand the information needs of these

users and operators of the transportation system to be able to treat, respond to or cope with weather threats.

• Covered all surface transportation decision makers– 426 needs across 44 decision maker categories

Micro-Scale Meso/Synoptic Synoptic/ClimaticD M#

Need# Warning Operational Planning

1.0 Infrastructure Operators

1.1 Highway maintainer (winter)1.1 control spreader application1.2 control plow1.3 control static (bridge) deicer1.4 observe/report1.5 navigate spreader/plow truck2.1 monitor conditions2.2 prepare2.3 select strategy2.4 assign crews2.5 prepare equipment2.6 activate staff2.7 initial dispatching2.8 contracting2.9 mid-storm management

2.10 cleanup3.1 devise response plan3.2 hire staff3.3 train staff3.4 buy equipment/services3.5 stock stores3.6 budget3.7 schedule seasonal tasks3.8 calibrate treatment controls

Examples of Needs

Decisions

TailoredDecision Support

-----------------filtering, fusion,

presentation

System

requirements

WIST-DSS

Actions

Road Weather Decision Support

(Information Infrastructure)

WeatherServices

Specialized RoadSensors

(ESS)

Communications

Interfacerequirements

Interfacerequirements

OtherITS

Interfacerequirements

Step 2 – Operational Concept Description

• Analyzed winter road maintenance decisions– Originally 10 operational scale decisions– Expanded to 53– Organized into 14 clusters

• Defined essential functions (i.e., system requirements) for the Weather Information for Surface Transportation – Decision Support System (WIST-DSS)

9, 77%

2.I Init. Dispatch

33, 60%

2.F Assign Crews

14, 56%

2.D Prep. Exp.

Time Before Event (Hrs., pseudo logarithmic)

100 030 10 3 -3

41, 40%

2.B Prepare

16, 72%

2.C Get Ready2.E Select Strat.

14, 75%

2.G Prep Equip.2.H Act. Staff

0, 96%

2.K Prime Disp.

3.8, 95%49, 46%

2.A Aware

29

Monitor Detect

Needs: Timing and Confidence

WIST-DSS Essential Functions

Update Clock

Select Context

GenerateScenario

UpdateContext

MonitorConditions

PresentDecision

MakeDecision

conditions_scenario

decision_situation

context_planning

context_parameters

time_local

time_universal

decision_operational

presentation_user

input_user

decision_selector

decision_criteria

scenario_selector

situation_selector

context_operational

decision_file

(to all processes)

context_update

context_selector

query_scenarioresponse_scenario

response_decision

query_decision

Primary InformationInterfaces Computer-Human

Interface

Step 3 – Preliminary Interface Requirements

• Linking decisions to threats• Linking performance threats and environmental

information• Synthesizing the Information Taxonomy

– 212 items necessary to support winter road maintenance decisions

– The 212 items include environmental information, transportation state information, and the treatment asset information.

Examples of taxonomy itemsEnvironmental Information2.1 Operational scale info. to Update Context 2.1.1 Weather 2.1.1.1 Winds 2.1.1.1.1 Wind direction 2.1.1.1.2 Wind speed 2.1.1.1.3 Wind situation 2.1.1.1.4 Maximum wind gust speed 2.1.1.1.5 Maximum wind gust direction 2.1.1.1.6 Stability

Transportation State2.1.5 Surface transportation network status 2.1.5.1 Road network 2.1.5.1.1 Segment characteristics 2.1.5.1.1.1 Traffic density 2.1.5.1.1.2 Traffic speed 2.1.5.1.1.3 Safe speed 2.1.5.1.1.4 Open/closed 2.1.5.1.1.5 Structure condition 2.1.5.1.1.6 Pavement condition (potholes, etc.) 2.1.5.1.1.7 Facility condition 2.1.5.1.1.8 Pavement type 2.1.5.1.1.9 Emissivity 2.1.5.1.1.10 Albedo

Asset Information2.1.4.3 Mobile treatment (crews) 2.1.4.3.1 Status 2.1.4.3.2 Equipment assigned 2.1.4.3.3 Beat completed 2.1.4.3.4 Dispatched beat 2.1.4.3.4.1 Treatment product type 2.1.4.3.4.2 Treatment product form 2.1.4.3.4.3 Percentage of treatment type in mix 2.1.4.3.4.4 Treatment amount 2.1.4.3.4.5 Treatment width

Linking Performance Threats and Environment Information

Performance

Threat

Road Condition

Atmospheric Condition

Threats most relevant to winter road maintenance treatment: Loss of traction

frozen precipitation on surface surface freezing (black ice)

temperature humidity precipitation (type, rate) winds/stability cloud cover insolation

Impaired plowing

snow/ice bonding (incl. surface freezing)

(all factors in surface freezing) precipitation (type, especially liquid content)

Lane obstruction

snow accumulation snow/freeze-related blowdown, slides and meltoff

winds severe storms precipitation (type, rate, history) icing (trees, wire lines) temperature (change rates, history)

Step 4 – Test & Evaluation

• Iterative development of operational systems• “Observing-to-outcome” chain

– Quantifying the relationships between performance improvements and environmental information quality

– Quality of decision support (Where’s the bottleneck?)

• Foretell evaluation – 1st comprehensive evaluation of the entire chain