High concentrations of pollutants at ground level during winter season are due to :
Answers
High pollutant concentrations are also found along busy roads. The concentrations can be especially high at motorway interchanges; and the Gravelly Hill Interchange, when opened in 1972 near Birmingham, rapidly came to be known as ‘Spaghetti Junction’, because its intertwining loops and ramps resemble a bowl of spaghetti. The term has come to be generally applied (e.g., converging of interstates: I-65, I-64, and I-71 in Ohio and as part of the 8664 Feasibility Study, Louisville Kentucky) and associated with the noise- and air pollution problems these junctions create. Road tunnels also become polluted; thus they require ventilation to keep traffic fumes at tolerably low values, but the vents can create localized high pollution concentrations.