Examples of road and traffic data that can be analysed to support an assessment of transport problems include:
- Traffic counts - from either manual classified counts (MCCs) or automatic traffic counts (ATCs), which are regularly collected by the appropriate road authority. These can be used for establishing the volume of road traffic, its composition and the extent and duration of peak periods. Count data can be used to establish growth trends and peak spreading effects. Advice on the conduct of traffic counts and their reliability is given in the Design Manual for Roads and Bridges (DMRB Volume 12).
- Journey time surveys - can be used to identify the impact of congestion on travel times, identify highly congested junctions and quantify delays. If journey time surveys have been repeated periodically over a number of years they can show how travel times and/or journey speeds have changed. Advice on undertaking journey time surveys is given in DMRB Volume 12;
- Roadside interviews (RSIs) - routinely collected for model development, RSIs collect much rich data that, other than its use in modelling, is often not analysed or presented in detail. Information available from RSIs includes journey purpose and car occupancy, both usually segmented by time of day. RSIs can also be used to collect data on parking and trip chaining amongst other issues. Advice on conducting RSIs is given in DMRB Volume 12;
- Accident data - there is a statutory obligation to collect data on personal injury accidents classified by severity. Accident data can be used to assess the number and severity of accidents; time trends can be identified and, if combined with a GIS, can easily be used to identify accident clusters or blackspots. The Scottish Government's Road Accidents Statistical publication includes details of all injury accidents reported by the police authorities in Scotland (see Section 17.2).
- Parking surveys - parking surveys can include a simple inventory, that is an assessment of the number of parking spaces in an area, appropriately segmented (long stay, short stay, PNR, public etc). More detailed surveys can include assessing occupancy of spaces, the duration of the study, the turnover of spaces and pricing structure;
