As one example of a crossing which does have warnings:<p>The A417 between Cirencester and Cheltenham is a dual carriageway that has  pedestrian footpaths across it.<p>Imagine driving at 70mph toward this:<p>350 yard warning: <a href="https:&#x2F;&#x2F;www.google.co.uk&#x2F;maps&#x2F;@51.8078399,-2.0618748,3a,75y,167.44h,96.69t&#x2F;data=!3m6!1e1!3m4!1sKTMpYzvV-A1YmgE5UK7BAw!2e0!7i13312!8i6656" rel="nofollow">https:&#x2F;&#x2F;www.google.co.uk&#x2F;maps&#x2F;@51.8078399,-2.0618748,3a,75y,...</a><p>actual crossing: <a href="https:&#x2F;&#x2F;www.google.co.uk&#x2F;maps&#x2F;@51.8051623,-2.0595278,3a,75y,167.44h,96.69t&#x2F;data=!3m6!1e1!3m4!1saNdFJWBbToa05d8ajkXiXA!2e0!7i13312!8i6656" rel="nofollow">https:&#x2F;&#x2F;www.google.co.uk&#x2F;maps&#x2F;@51.8051623,-2.0595278,3a,75y,...</a><p>350 yards at 70 MPH is, I think, 10 seconds.