Transport emissions in 2004 amounted to +26% of all world energy, 95% of transportation using oil based fuel.Policies have been put in place in various countries to try and reduce the emissions, such as Land and transport planning; taxation and pricing; regulations and traffic management; fuel economy guidelines; In addition to policies, improved technologies the most promising strategy, such as hybrids, electric powered trains, fuel cells and battery cars offer the most. The use of other fuels such as natural gas, bio fuels and hydrogen also help to mitigate the effects of transportation on the environment.