Road Weather Station for Highway Safety Monitoring

JW-TWS2(HY11) Road Weather Station is a fixed roadside environmental monitoring system designed for highways, expressways, bridges, tunnels, mountain roads and other traffic infrastructure.

It continuously collects local weather, visibility and road-surface data to help road authorities identify conditions that may increase the risk of:

• Road icing
• Wet or water-covered pavement
• Snow accumulation
• Low visibility
• Strong crosswinds
• Heavy rainfall
• Fog and haze
• Freezing conditions
• Rapid pavement-temperature changes

The system can combine atmospheric sensors, non-contact road-surface sensors, visibility sensors, precipitation monitoring, cameras, a roadside data logger and remote communication equipment.

Data can be transmitted to a traffic management centre, highway maintenance platform, cloud dashboard or third-party Road Weather Information System for real-time display, historical analysis, alarm management and maintenance response.

What Is a Road Weather Station?

A road weather station is a roadside monitoring system that measures atmospheric and pavement conditions affecting traffic safety.

A general weather station mainly describes the surrounding atmosphere. A road weather station additionally focuses on the conditions experienced by vehicles and the road surface.

Typical measurements include:

• Air temperature
• Relative humidity
• Dew point
• Wind speed
• Wind direction
• Rainfall
• Precipitation type
• Visibility
• Road surface temperature
• Road surface condition
• Water-film thickness
• Snow depth
• Camera images

This combination helps operators understand whether a road is likely to remain dry, become wet, freeze, accumulate snow or experience reduced visibility.

Why Highway Weather Monitoring Is Important

Weather conditions can change rapidly along a road corridor.

A regional weather forecast may not represent conditions at:

• A bridge deck
• A mountain pass
• A shaded road section
• A tunnel entrance
• A tunnel exit
• A river valley
• A coastal highway
• A high-altitude section
• A fog-prone lowland
• A historical icing location

Local monitoring provides information directly from the affected road section.

The data can support:

• Winter road maintenance
• De-icing decisions
• Snow-removal planning
• Speed-limit adjustment
• Variable-message signs
• Road-closure decisions
• Driver warnings
• Bridge crosswind warnings
• Inspection scheduling
• Post-storm assessment

Technical Parameters

Road Weather Station vs General Weather Station

Parameters That Can Be Monitored

The final configuration should be selected according to the project’s road type, climate and risk objectives.

Air Temperature

Air temperature provides the background condition for:

• Freezing-risk assessment
• Snow and sleet analysis
• Frost conditions
• Equipment compensation
• Winter-maintenance planning

Air temperature alone does not confirm whether the road surface is frozen.

Relative Humidity

Humidity helps assess:

• Condensation
• Fog formation
• Frost risk
• Surface-moisture conditions
• Atmospheric moisture before freezing

Dew Point

Dew point can help determine when surface condensation or frost may become more likely.

When the road-surface temperature approaches or falls below the dew point, moisture may condense or freeze depending on the thermal conditions.

Wind Speed and Wind Direction

Wind monitoring supports:

• Bridge crosswind warnings
• High-sided vehicle risk assessment
• Snow drifting analysis
• Fog movement interpretation
• Precipitation exposure
• Storm-response planning

For bridges and exposed mountain roads, wind gusts may be more operationally important than average wind speed.

Rainfall and Precipitation

Rainfall or precipitation sensors can support:

• Rain-event detection
• Rainfall intensity monitoring
• Heavy-rain warning
• Rain–snow transition assessment
• Freezing-rain risk analysis
• Drainage and flooding assessment
• Maintenance scheduling

Visibility

Visibility may be reduced by:

• Fog
• Haze
• Heavy rain
• Snow
• Blowing snow
• Dust
• Smoke
• Spray from traffic

A visibility sensor can provide objective distance data for speed-control and warning systems.

Road Surface Temperature

Road-surface temperature is one of the most important parameters for winter road monitoring.

It may differ significantly from air temperature because of:

• Solar heating
• Night-time radiative cooling
• Bridge-deck exposure
• Surface material
• Traffic
• Shade
• Wind
• Stored ground heat

Road-surface temperature should therefore be measured directly or through a suitable non-contact pavement sensor.

Road Surface Condition

A road-surface sensor can identify or estimate conditions such as:

• Dry pavement
• Damp pavement
• Wet pavement
• Standing water
• Snow
• Ice
• Slush
• Frost-related surface conditions

For dedicated non-contact pavement monitoring, see the Road Surface Condition Sensor for Highway Safety.

Water-Film Thickness

Water-film data can help distinguish light surface moisture from deeper standing water.

This can support:

• Aquaplaning-risk assessment
• Drainage evaluation
• Winter freezing analysis
• Rain-event response

Snow Depth

Snow-depth monitoring can support:

• Snow-removal planning
• Lane-closure decisions
• Mountain-road management
• Winter road reports
• Maintenance verification

Camera Monitoring

A camera can provide visual confirmation of:

• Snow cover
• Fog
• Rain
• Traffic conditions
• Road blockage
• Maintenance activity
• Flooding
• Surface contamination

Camera data should complement sensor measurements rather than replace them.

How Road-Icing Risk Is Evaluated

Road icing should not be judged from air temperature alone.

A more reliable assessment may combine:

• Road-surface temperature
• Air temperature
• Relative humidity
• Dew point
• Precipitation
• Road-surface moisture
• Water-film thickness
• Road-surface status
• Wind
• Historical cooling trend

For example, a road may remain above freezing even when the air temperature briefly drops below 0°C. Conversely, a bridge surface may cool below freezing while nearby ground-level roads remain unfrozen.

The monitoring platform can combine several variables to generate a risk level, but final alarm logic should follow the road authority’s engineering criteria.

System Architecture

A typical Road Weather Information System architecture is:

Road Weather and Pavement Sensors
→ Roadside Data Logger or RTU
→ 4G / Ethernet / LoRaWAN / Fibre Network
→ Traffic Management Centre or Cloud Platform
→ Dashboard, Alarm, VMS and Maintenance Response

Field Monitoring Layer

The field layer may include:

• Automatic weather station
• Road-surface condition sensor
• Visibility sensor
• Precipitation sensor
• Snow-depth sensor
• Camera
• Water-level sensor
• Roadside enclosure
• Solar power system

Data-Acquisition Layer

The roadside controller can collect data through:

• RS485 Modbus RTU
• Analogue inputs
• Pulse inputs
• Digital inputs
• Ethernet
• Camera interfaces

Communication Layer

Available communication methods may include:

• 4G LTE
• Ethernet
• Fibre optic network
• LoRaWAN
• NB-IoT
• Private traffic communication network
• Satellite communication for selected remote roads

Platform Layer

The monitoring platform can provide:

• Real-time road-weather data
• Road-section map display
• Historical trend curves
• Ice and snow warnings
• Visibility alarms
• Crosswind alarms
• Rainfall alarms
• Sensor-fault alarms
• Communication-loss alarms
• Camera images
• Maintenance records
• Data export
• API integration
• Variable-message-sign integration

Typical Applications

Expressways and Highways

Road weather stations can be installed at high-risk sections to support:

• Winter operations
• Traffic management
• Maintenance dispatch
• Speed-limit decisions
• Incident prevention
• Driver information systems

Bridge Weather Monitoring

Bridge decks may cool differently from road sections supported by the ground.

Bridge monitoring may include:

• Road-surface temperature
• Air temperature
• Humidity
• Wind speed
• Wind direction
• Precipitation
• Surface status
• Camera

Strong crosswind and rapid bridge-deck cooling are common reasons to prioritize bridge monitoring points.

Tunnel Entrances and Exits

Tunnel portals can experience rapid changes in:

• Visibility
• Pavement temperature
• Moisture
• Wind
• Fog
• Snow
• Ice

Sensors should be positioned so that the monitored section represents the actual portal risk rather than conditions deep inside the tunnel.

Mountain Roads

Mountain roads may face:

• Sudden temperature changes
• Fog
• Snow
• Icing
• Strong wind
• Avalanches
• Landslides
• Limited communication
• Long emergency-response times

Recommended equipment may include pavement sensors, visibility sensors, snow-depth sensors and cameras.

High-Altitude Passes

High-altitude roads often require:

• Low-temperature equipment
• Solar-power design for winter
• Snow and icing monitoring
• Wind monitoring
• Anti-condensation protection
• Reliable remote communication
• Reinforced mounting

Coastal Highways

Coastal roads may face:

• Strong wind
• Salt spray
• Heavy rain
• Fog
• Corrosion
• Storm surge
• Reduced visibility

Corrosion-resistant mounting, connectors and enclosures should be selected.

Urban Elevated Roads

Elevated roads may require monitoring of:

• Crosswind
• Surface temperature
• Rainfall
• Visibility
• Traffic-related spray
• Local icing
• Environmental noise

Fog-Prone Road Sections

Visibility sensors should be installed at locations with a history of:

• Dense fog
• Valley fog
• Coastal fog
• Smoke
• Haze
• Blowing snow

Monitoring-Point Selection

Monitoring points should be selected according to risk, not only by equal spacing.

Priority locations include:

• Historical icing points
• Bridges
• Tunnel entrances and exits
• Mountain passes
• Shaded sections
• River valleys
• Fog-prone areas
• High-wind sections
• Sharp elevation changes
• Flood-prone road sections
• Snow-drift locations
• Accident black spots

A long highway may require multiple stations because weather and pavement conditions can vary significantly between sections.

Installation Recommendations

Select a Representative Road Section

Install sensors where conditions represent the target risk.

Avoid locations where local heat, shade or drainage produces data unrelated to the monitored road section.

Avoid Wind Obstruction

Wind sensors should be positioned away from:

• Signboards
• Lighting poles
• Buildings
• Noise barriers
• Trees
• Bridge structures
• Camera masts

that may cause turbulence or wind shadow.

Install the Road Sensor Correctly

For a non-contact road-surface sensor:

• Maintain the specified mounting height;
• Aim at a representative lane surface;
• Avoid road markings where possible;
• Avoid areas frequently covered by stationary vehicles;
• Keep the optical path clear;
• Prevent the bracket from moving.

Position the Visibility Sensor Carefully

Avoid:

• Direct sunrise or sunset glare
• Headlight glare
• Exhaust plumes
• Water spray
• Permanent traffic obstruction
• Nearby reflective surfaces

Protect the Camera Field of View

The camera should clearly show:

• The monitored lanes
• Road shoulder
• Surface condition
• Relevant visibility conditions

Avoid strong backlighting and structural obstruction.

Protect the Roadside Cabinet

The enclosure should include:

• Waterproof cable glands
• Surge protection
• Grounding
• Lightning protection
• Ventilation or thermal control
• Battery protection
• Secure locks
• Anti-vandal design where required

Evaluate Solar Power

Solar-system sizing should consider:

• Sensor power consumption
• Camera power
• Transmission frequency
• Heater use
• Winter sunlight
• Consecutive cloudy days
• Battery ageing
• Low-temperature battery performance
• Snow covering the panel

Communication Options

4G LTE

Suitable for dispersed roadside stations where cellular coverage is available.

Ethernet or Fibre

Suitable for highways with existing intelligent-transport communication infrastructure.

LoRaWAN

Suitable when several sensors are deployed within gateway coverage and data volume is relatively low.

Alarm and Response

Possible alarms include:

• Road-surface temperature approaching freezing
• Ice or snow detected
• Wet pavement under freezing conditions
• Water-film threshold exceeded
• Visibility below threshold
• High wind or crosswind
• Heavy rainfall
• Snow-depth threshold exceeded
• Communication failure
• Sensor fault
• Low battery
• Cabinet intrusion

Alarm thresholds should be configured according to:

• Local climate
• Road geometry
• Bridge design
• Vehicle type
• Speed limit
• Historical incidents
• Maintenance capability
• Road authority procedures

Road Weather Station vs Standalone Road Sensor

Request a Road Weather Station Configuration

Send JW-IoT your highway location, road type, historical weather risks, required sensors, communication coverage and platform requirements.

Our team will help configure a suitable road weather station, pavement monitoring sensors, roadside communication equipment and remote warning platform.

Request a Quotation

Explore Traffic Sensors

View the Integrated Road Weather Station

View the Road Surface Condition Sensor