Warm Mix Asphalt (WMA) technologies allow significant lowering of the production and paving temperature. By reducing the viscosity of bitumen and/or increasing the workability of mixture, WMA technologies can reduce the temperature up to 80 degrees below the temperature of conventional Hot Mix Asphalt without compromising the performance of asphalt. This promises various benefits over HMA, e.g. lowering the greenhouse gas emissions, lowering energy consumption, improved working conditions, better workability and compaction, etc. However despite the promising performance in comparison with HMA, this technology has not yet gained wide acceptance in asphalt industry. In order to reach widespread implementation it is necessary to prove that WMA has the same or better characteristics and long term performance as HMA. This book includes detailed review of the WMA benefits, drawbacks, potential problem areas and the possible specialisations for implementation of WMA. A total of twenty two WMA products are reported including a description of the temperature reduction principle, the basic characteristics and production technology with necessary plant modifications.