Stage 1: Assessing the Travel Characteristics of a Development: Available databases
Estimating travel generation and modal split requires appropriate data. However the suitability of data for Transport Assessments is of variable quality, with much depending on the type of area that a development is proposed in, and the resources available to the developer undertaking the assessment.
Trip generation databases are an important source of information on car travel. Unless the data contains information on non-car modes, they should be employed with caution in Transport Assessments – possibly as a starting point for the base level of travel and modal share for example. In addition, their use may tend to replicate past travel patterns, thus encouraging developers to provide for more car travel than is necessary, rather than promoting sustainable modes.
Nevertheless, for the present, these databases remain necessary tools, since they provide more information on behaviour than other surveys. Furthermore they are now being changed to allow inclusion of data for modes other than the car.