David Simmonds Consultancy Limited


Suite 4, Bishop Bateman Court,

5-7 New Park Street, 

CB5 8AT, Cambridge, England 

Phone: +44 (0) 1223 316098


112 George Street, 

Edinburgh, Scotland EH2 4LH

Phone +44 (0) 131 226 5908

DELTA urban models

The six processes at the urban level are:

  • the development process
  • changes in the quality of residential areas
  • demographic change (eg household formation) and economic growth
  • car-ownership choices
  • location and relocation of households and jobs in the property market
  • changes in employment status (working/non-working) and commuting patterns.

The six models dealing with these processes or groups of processes are all run within each time period, as shown in Figure 2. All of these models interact, with various timelags between the different processes of change. Changes in accessibility and environment, due to the workings of the transport system, directly influence location/relocation choices. These choices influence the property market, which influences developers’ decisions, and hence transport has an indirect influence on the development process.

Figure 2

Click here for details of DELTA applications.

Simplified DELTA models can be developed by reducing the level of detail or by omitting certain processes. For example, we developed a very simple residential location model for the Borders Railway Reopening Study using only two components of DELTA - the accessibility calculations and the location sub-model - and a single category of households.



David Simmonds Consultancy Limited is registered in England and Wales, company registration 04860878. The registered office is 10 Jesus Lane, Cambridge CB5 8BA