MD National Road:
Eastbound uses Mulberry and westbound uses Locust in Hagerstown. Neither direction uses Potomac.
Eastbound in Frederick uses East Street, while MD 144 east continues to Franklin. But westbound is the same. So should the overlap be broken or not?
Here I've kept the overlaps along Mulberry (with US40Alt) and Patrick (with MD144) as concurrent with those routes, but this can be changed. Both existing routes are not well mapped.
So the Frederick situation is a nice hot mess. Officially, only Patrick Street is part of the state highway system as MD 144. But Patrick becomes one way westbound west of East Street, so where's MD 144 eastbound? Officially currently, nowhere, but formerly it used South St to Franklin St before those were downloaded to local maintenance. At least one or two signs or MD 144 east along this alignment remain in place. So, by the principle of "there are no one way routes, if a route officially only follows a one-way street there must be an implied one-way pair", MD 144 is mapped as though what used to be officially its eastbound routing was not dumped.
The National Road being run through the area using a slightly different one-way pairing makes properly mapping this impossible since whether the two are concurrent between East St and Franklin St depends on which direction you are traveling.
But I do think leaving it as is as the least bad solution.
Over in Hagerstown, I see no reason not to map it as signed, but yes this requires adjusting US40AltHag and US40's files to create waypoints in the right place. I can appreciate Si did not want to mess with other people's stuff but as this is mine I'll go ahead and do it.
EDIT:
https://github.com/TravelMapping/HighwayData/pull/7332Also made a few adjustments in Baltimore to accommodate