In undertaking its research, BITRE is often required to estimate the likely consequences of changes in market conditions or potential policy changes. In order to do this, it uses estimates of the likely responsiveness of transport to such changes referred to as elasticities. For example, how is the amount of car travel affected by the costs of running a car, or the price of public transport. To improve how it conducts analysis BITRE has, over the course of many years, systematically collated information on transport elasticity estimates produced by empirical studies. BITRE's database is made freely available here as a resource for transport analysts, policy makers and anyone else interested in transport issues.