This paper describes the first stage of the development of the Network Information System (NIS), a computer database designed to provide information to assist in the management of the motorway and trunk road network. When fully developed, the system will hold the following main groups of data for all motorway and other trunk roads: (a) inventory data such as road furniture; (b) construction details of existing highways and structures; (c) condition data for existing roads; (d) operational data such as accident rate statistics or traffic flows; and (e) forward planning data. These data will be analyzed by sets of software applications. The applications to date are as follows: (1) The network location referencing NISR application. This consists of a two level model of the motorway and trunk road network, all other A-roads and many B- roads. The higher level network is used as the basis for the national traffic census. Each section of the network has been allocated a census point at which a count is taken every 6 years. The level 2 network is a disaggregation of the level 1 network to take into account minor junctions and administrative boundaries. NISR has an associated suite of programs to enable the network to be maintained to take account of new construction etc. It includes: (1) a graphics facility for displaying the network and the proposed changes, which can be operated through a series of menus. (2) The traffic application. This holds traffic estimates for all sections of the road network. The application allows data to be extracted for a wide range of user specified variables including location, road type, number of lanes etc. (3) The Accident application. Selected parts of the Stats 19 records of accidents are held in NIS. A number of options are available for analysing the data to present information to assist the identification of problem road sections. Accident rates can also be calculated by correlating the accident data with the traffic data.
Abstract