The Base MapOne source reliable enough to be used as the basis of the new map was the 1st edition 1" OS map dating from 1830-1833, when the turnpike system had reached its fullest extent. I chose to work from the David and Charles reprints for the convenience of scanning folded sheets, rather than copying larger sheets photographically which would have lost the accuracy inherent in the scanning process. The condition map covers the whole of the modern county.
How It Was DoneI started with a grid corresponding to the 10-km OS national grid squares for Oxfordshire, marked by the blue cross-hairs. This was the space in which to fit 20 or so map segments, each derived from an A4 scan of a part of the base map. The difficulty was to place these segments accurately on the grid, especially since the exact orientation of the scans couldn't be relied on. The solution was to fix the position of a few key features (such as road intersections) by means of crosses on the grid, from their modern map references. Then it was only necessary to position each segment so that the features overlaid their corresponding crosses, hopefully linking up roads from neighbouring segments at the same time. The crosses, intended only as draughting aids, were removed afterwards so that they don't appear on the final map. I've aimed to get all features on the finished map to within 0.1 mile of their true positions.
Symbols For the Mile MarkersMarkers known to have existed after the date of the base map but now lost are shown as rather ghostly grey circles filled with white. Milestones which have survived appear as black circles filled with colour, and surviving mile posts (that is ones made of metal or having metal plates) as black squares filled with colour. The few known survivors which have been taken away from the road they were on to an out-of-context location are marked by colour-filled triangles at their original positions. Examples include the 57- and 59-mile markers near Bletchingdon, which were moved "for safe keeping" to the north of the village, and the 13-mile stone north of Hopcroft's Holt, which was rescued during road works and now decorates the County Council office forecourt in Oxford.
Condition ColoursThe red, amber and green (traffic light) fill colours of the surviving mile markers give a general idea of their condition, related to their "fitness for purpose". In brief, a marker coloured green has a completely readable legend and is not obviously at risk. However, it may not be in pristine condition. Amber markers are those where the legend is not fully readable or where they are at risk through erosion or damage. Red markers have no readable legend, are seriously at risk or misplaced eg. in a ditch.
The colours are based on the information in the "condition-stone" and "condition-letters/plate" fields of the database and are intended as a quick reference only, not as a replacement for the detailed information in the database. Green markers are those whose stone is G(ood) or has M(inor chips), or whose letters are G(ood) or F(aint). Amber marker stones are E(roded) or the letters are M(ostly readable) or P(artly readable). Red marker stones are D(amaged or deteriorated), B(adly broken), the letters are U(nreadable), X(attachment lost), or F(allen).
DestinationsAs I chose the 1st edition 1" as my base map, I have also stayed with its choice of destinations, as implied by the mileages shown, where possible. These place names or those at the end of a route are considered destinations, and are given the accolade of upper-case lettering and a ring round the town.
Go back to the Oxfordshire condition map, or return to the map home page.