18.1.1
The type 66 PRoW and type 67 ASD Coordinate Records allow an accurate copy to be made of the information in the Definitive Map and Statement. In the previous version of the DEC-NSG v3.6 March 2014, Appendix E described two different methods which because of the introduction of DTF8.1 were moved into a single method that is essentially the Definitive Map method.
18.1.2
The additional information that can now be included in the type 66 PRoW and type 67 ASD Coordinate Records using DTF8.1, if available in the users’ system, is intended to help integrate it with the definitive statement. The only time that a line shown for a PRoW in the NSG does not follow the definitive map is when it is within the extent of another Highway – in this case the type 67 ASD Coordinate Record can show what the Definitive Map intended to indicate.