Marketable permits (or quotas) for emissions of pollutants have proven their effectiveness in controlling sulphur dioxide emissions by U.S. power plants, or for the rapid elimination of lead in gasoline in the 80 in the USA. With regard to greenhouse gas emissions, the European Emission Trading Scheme on stationary installations has been operational since 2005. Is this type of instrument applicable to transportation, considering the nuisances they generate (congestion, noise, air pollution, greenhouse gas emissions)? This book introduces the concept of marketable permits and analyses their relevance for the various nuisances of transportation. It presents some examples of applications and reviews a number of proposals. Potential application areas are identified, with particular developments as regards CO2 emissions from transport.