RoadWX a service provided by GWC RoadWX services provided by GWC


Road Surface Conditions and
Forecast Data Services

Global Weather Corporation’s RoadWX™ service provides estimated road surface conditions and forecasts for any road location in the world – whether that location is associated with Road Weather Information Sensor (RWIS) data or not. RoadWX delivers accurate estimates of road conditions to enable applications such as road weather warnings, navigation guidance, and route optimization. Typical users include commercial fleets, consumer vehicles, and transportation departments. When available, connected vehicle data is used to modify and improve the forecast.

RoadWX combines two critical modeling steps, as shown in this diagram. The first is GWC’s best-in-the-world atmospheric forecast.1 The second is our road physics model, which utilizes radiation transfer algorithms to compute road surface (concrete or pavement) temperature using current weather and road state history as inputs. Accurately predicting road temperature is critical to forecasting road state correctly, making it possible to distinguish between snowfall melting on warm roads or accumulating on cold roads.

GWC road temperature accuracy has been verified by comparison to RWIS observations, shown to the right. As shown in the map below, RoadWX forecasts can distinguish between key road states (dry, wet, snow, and ice) even within a localized area.

GWC | Modeling for Pavement Temperature and Road Conditions
GWC | RoadWX Real Time Road Conditions Map


RoadWX data is generated at hourly and sub-hourly intervals, with forecast lead times available to 48 hours. It includes both atmospheric weather variables and road surface variables (road temperature and condition), as summarized below.

Two versions of RoadWX are available:

  • For user-defined intervals (such as every 1/2-km) along roads anywhere in the world
  • At RWIS sensor locations

Data for RoadWX Services


Atmospheric Variables

  • Temperature
  • Wind Speed
  • Wind Direction
  • Precipitation Amount
  • Precipitation Type: Rain, Snow, Mix, Sleet, Freezing Rain

Road Conditions

  • Road Temperature
  • Water Depth
  • Snow Depth
  • Road State: Dry, Wet, Wet/Drying, Slush, Snow/Ice
  • Impact Codes (Worst-case, Hazards)


  • Bulk, CSV format through standard secure HTTPS web services
  • On Demand, requested via API and delivered in XML format through restful web services using the URI/http method

1. According to ForecastWatch, an independent provider of forecast accuracy and skill information, GWC’s forecast was the best for 2013, 2014, and 2015. All reports are available at



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