This has been carried out using category analysis techniques on survey data for a limited number of stations. Profiles for observed situations have been developed and applied across the network. The authors of the work recognise that this process has severe limitations, and detailed analysis of the data for the study area in question is recommended prior to a decision to make use of this source. Further data processing for the DETR has been conducted to segment the demand by purpose and car availability. Outputs from the database can be spreadsheet listings, printouts of GIS maps, or a GIS point dataset.
Detailed maps showing site locations are available.
The DETR has an extensive database of traffic counts. The Highways Agency also has a large amount of traffic count data. It is expected that full use will be made of this information. Analysts should ensure that data collected for the Studies includes, as a minimum, all those variables specified in the DMRB, Volume 12, section 6.5. Additional variables may be collected, though analysts should bear in mind the need to minimise the time required to conduct each interview.