Volume Two 2. General Rules Figure 2.9: Railway Crossing Sightlines 2.32.4.22. Where a new vehicle crossing is to be formed to a national route (as identified in Appendix 17) and the access crosses a railway and there is less than 25m separation between the national route and the railway the sight distance must be measured from a point: (a) at a height of 1.15m above the proposed surface level of the access; (b) on the access; (c) 5m back from the side of the railway furthest from the national route. 2 – 51