How Does the Road Weather Information System Work?
The RWIS applies technology to decision-making. It uses specialized equipment and computer programs to monitor air and pavement temperatures and predict whether precipitation will freeze on the pavement.
Sensors collect real-time data on air and pavement temperatures, precipitation, and the amount of deicing chemicals on the pavement. These are combined with information from value-added meteorological services to predict pavement temperatures for a specific area, such as a mountain pass, over a 24-hour period.
These predictions are then transmitted to a computer at the highway agency's winter maintenance center. This information is critical to an effective anti-icing strategy, since deicing chemicals must be applied about an hour before the pavement reaches freezing temperatures. This prevents ice from forming on the pavement, in contrast to traditional methods in which the ice is cleared after it has already bonded to the pavement.
Using portable computers linked by modem to the central computer, maintenance managers can monitor conditions and advise motorists and dispatch crews as necessary.
