Kathmandu, June 3 Minister of Home Affairs Ram Bahadur Thapa and Minister of Forest and Environment Shakti Bahadur Basnet took the people by surprise as they appeared on the road to conduct vehicle emissions test this morning. Almost 50 per cent of vehicles, which went through the test, exceeded the emissions level set by the government. According to the Department of Environment, a total of 24 vehicles — 11 petrol engine and 13 diesel engine —  were tested. Among them nine petrol engine vehicles and four diesel engine vehicles passed the test, while 11 vehicles exceeded the emissions level. Three vehicles were found plying the road without valid green stickers, according to DoE officials. According to the government standards, petrol engine vehicles should maintain three or less than three per cent carbon monoxide and 1,000 ppm hydro carbon. Similarly, diesel engine vehicles should maintain smoke opacity of 65 HSU. The DoE has claimed that they conducted vehicle emissions test on 1,374 vehicles in the last six months. Of them,  635 vehicles failed the test.