Abstract
In order to verify the NOx reduction effect due to traffic control, nitrogen oxides (NOx) were determined on the mountain road of Mt. Fuji one day a week from the end of July to the beginning of September, 2012, using a NOx analyzer and an electricity supply system which were installed in a monitoring car. The average concentrations per day of NOx in and out of the traffic control period were measured as 6.2 ppbv and 15.9 ppbv, respectively. The traffic control reduced the NOx concentration to 39%. The NOx reduction effect by the traffic control was confirmed by the observation. The average number of automobiles that used the mountain road was 105±31 when traffic congestions occurred during the observation period. The concentrations of NO per vehicle were estimated as 0.05±0.03 ppbv and 0.22±0.04 ppbv for the number of automobiles less than 110 and exceeded 110, respectively. The concentrations of NO per vehicle increased when the number of automobiles was around 110, which might be caused by the traffic status changing from an ordinary condition to congestion.
