Background and definitions
6.1.1
BS7666 defines three types of Street geometry which are based upon the levels of detail required to describe the extent of the Street. The NSG is based upon level 3 geometry. Whereas, currently, the ASG for addresses is predominantly based upon a level 1 geometry. It is however recognised that in the early pre-development stages of the life cycle of a Street, level 1 geometry may be required if suitable mapping data is not available. For details of the life cycle of a Street, see Appendix D.