Why do crews focus on the pavement temperature rather than the air temperature?
Air temperature is not usually a good indicator of what the roadway surface temperature actually is. During the fall, the pavement is often kept warmer than the surrounding air because of the warm soil. During the spring, the reverse may be true; the pavement temperatures can be colder than the air because the soil is still frozen from the long winter temperatures. The sun also has a strong influence on the pavement temperatures that will help heat the pavement and help the melting process. The difference between air and pavement temperatures can often differ by as much as 20 degrees Fahrenheit.