Well, I was wrong about the timing. Either that, or I'm slacking at work. Whatever the case, usatn is ready for peer review now.
Generally speaking, the main sources I used were the
TDOT functional classification maps. On the positive side, they show TDOT-maintained and signed routes fairly clearly. On the negative, when TN routes follow US routes, these maps show concurrencies even in cases where the TN route is unsigned. I turned to GMSV to determine which concurrencies were signed.
My criteria for splitting routes into signed segments are explained below, and in almost all cases I kept to them. This sometimes resulted in me drafting routes that didn't exactly match what was posted in the field, mainly because what was posted was inconclusive or misleading. Example: according to signage in the field,
TN54 turns south to follow US45E in Greenfield, but then signage stops. West of Bradford on US45E,
TN54 is shown heading east and west, and
it's also signed between US45E and TN105 in Bradford. I'm leaning towards changing it into two segments, one from Greenfield east and the other from 105 in Bradford west, but am open to suggestions.
Waypoint labels were based first on street signs as shown in GMSV, then
property descriptions, then, if both failed, on OSM. OSM disagreed with what was posted/recorded enough that I lack confidence in its accuracy in Tennessee, especially in rural areas.
I also preferred using shaping points to named waypoints in places where the intersecting road was insignificant, so shaping points positioned near intersections with dead-end or other minor roads are usually intentional. This was meant to limit the number of less useful waypoints cluttering the lists in especially curvy roads, of which the state has plenty. I'll gladly add named waypoints for any user who needs one somewhere.
If anyone wants to see the spreadsheet with my notes on every route, just ask. I'll post it on Google docs.
