Pollutant emission
Pollutant emission: particulates accumulating on road surface, which are produced by different sources, not only by vehicles (including direct emission with fumes, and also tires, linings, and road deterioration), but also plants or near sources, e.g. industrial or municipal emitters. These particulates can be re-floated by turbulences generated by cars or by gusts of wind. Re-suspension is probably one of primary sources of coarse particulates emission near communication routes. Measures conducted in France indicate that the source of particulate matter is approximately 3 to 7 times more efficient than direct emission from car fumes. Crucial for the emission of particulates is also highway maintenance during winter (sprinkling and salt on roads), thus road cleaning is important in improvement of the air quality.