Stage 1: Assessing the Travel Characteristics of a Development: Estimating the travel generated and likely modal split
The estimation of how many people will travel to the site and by what mode (or in the case of housing, from the site) can be undertaken by several methods. Here only the simple approach is described. This requires consideration of the:
- location of the site including:
- how many people are living within the travel time isochrones by each mode; and
- the likely propensity of people within each catchment to use the proposed facility.
- size of the catchment area: larger catchment areas (often for larger developments) imply a higher modal share for car-use but also offer more potential for public transport use.
- use of the development including:
- whether people need to carry bulky items to or from it; and
- whether people will be likely to visit the site as part of a linked-trip to other locations, for example for pass-by shopping.
- design and layout within the site: how it helps or hinders access by different modes and adds to or reduces travel times.
- measures taken to influence modal split and how they are likely to influence the choice of mode.
Within a Transport Assessment it will only be possible to make broad estimations using these factors.
Estimating the travel generated and likely modal split contains the following sub categories:
- Available databases
- Trip rate
- Research on measures to influence modal split
- Person-trip travel surveys
- Estimating modal split