energy and environmental issues in transport sector

nowadays, transportation sector consumes about 27 percent of the whole energy in iran. therefore, after domestic and business sectors which consume about 40 percent of the whole energy, transportation is placed in the second rank. however, the financial value of transportation is of the highest importance. moreover, having 55percent of gasoline product consumption transportation has been also ranked as the largest consumer of gasoline products. gasoline consumption in transport showed an increase until 1979. during 1980-1981, it decreased slightly and from 1982 have had a permanent upward trend. oil products consumption in transport sector in 1950 has been less than average 15 million barrels (equivalent to crude oil) per year. in 1990, the above amount was approximately 140 million barrels per year, while in 2000; this amount was 20.7 times more than 1960s. gasoline consumption in transport sector is about 98percent of the whole gasoline consumption in iran. since gasoline burning vehicles are consuming nearly all gasoline supply in the country; thereafter vehicle number is a determining factor in estimation of gasoline consumption. investigations showed that the number of gasoline burning vehicles has increased constantly from 1960. the activities of domestic automotive factories have increased since 1970. excessive demand for personal cars in 1990 and 2000s have caused enormous amount of cost for government to import gasoline and gas oil yearly. thereupon, the energy management seems to be an inevitable necessity for transport sector. during the past ten years, by increasing car ownership and the moderate prosperity, the ratio of trips from 1.5 million has been reached to almost 15 million travels during the day. this huge number causes many other problems such as consuming about 12 million liters gasoline by vehicles in tehran. more than 2 million vehicles are traveling in tehran during a day. tehran bus system can transfer about 1 billion passengers and the subway system transfers about 200 million passengers annually.