It passes through Godstone and Felbridge, then follows an almost straight line through Ardingly, Haywards Heath, Burgess Hill and Hassocks to the South Downs at Clayton.
[3] In 1818 Reverend James Douglas looked at these findings and surmised that this was part of a road to a port in the Portslade area.
A paper published in 1999 by Glen Shields on the topography of the Hassocks and Clayton area concludes that the road took a more westerly route over Clayton Hill than proposed by Margary, and that a traceable route to Portslade would have been more practical and more in keeping with Roman practice elsewhere than going along the valley bottom to Brighton.
[5] Margary concluded that four main alignments were used for the road as far as the South Downs, with local diversions from them to ease gradients and avoid wet ground.
[1] Before the area was built over Owen Manning and William Bray noted this route in their History and Antiquities of the County of Surrey (1814), saying that the line "took its course by Old Croydon and the West side of Broad Green where it is still visible".
[8] Further possible support to the theory is given by a title deed of the late 1280s, by which a piece of property, described as lying on the east side of the king's highway in Old Town, was sold by one "Andrew de Calceto in Croyndon", also named as "Andrew ate Causie", both forms of his name meaning "of/at the causeway", a term which implies a well constructed road.
Against the Old Town theory is the fact that the area (lying in the headwaters of the River Wandle) would have been extremely marshy, and that it would have been more logical for the Roman engineers to have followed the higher and dryer ground, and straighter alignment, of the easterly High Street route.
[10][11][12] A compromise argument would see the road following the Old Town route as far as Duppas Hill, but then cutting across the Wandle valley to Riddlesdown.
Between Tilburstow Hill and Blindley Heath Margary noted large hedgebanks set back on either side of the modern lane, indicating the overall width of the road, adapted as a medieval droveway.
[1] This longest alignment, at 28 kilometres (17 mi), follows a mostly straight course across the Weald, with minor diversions to avoid steep or wet ground.
The line north of this to Green Wood was adjusted 11 degrees to the east to avoid wet ground.
[15] Going through central Burgess Hill it passes the west side of the parish church, where its course is marked by brass plaques set into the modern road surface.
At the crossroads with the Sussex Greensand Way at Hassocks there is a large Roman cemetery in the south west corner.
This track, now a bridleway, reaches the summit at 155 metres (509 ft), then gently descends to Pyecombe as a broad and well-constructed terraceway along the west side of Wish Bottom.