Hi, if there are folks out there who're thinking about mapping this on-ground, then sharing some unsolicited and untested ideas:
A real-world requirement for many logistics / transport folks is : which of the roads are too narrow to send my truck / 4-wheeler / tempo / e-rickshaw through?
And frankly the people living there may also appreciate if map routers stopped sending wide bodied vehicles through their lanes.
Then, in many cases it might not be the whole stretch of road, but just the narrowest bottleneck on it that matters, as that point will decide what can (or rather shouldn't) pass through.
So, mapping of just the narrowest points instead of lengths also cuts down your task load and reduces the scale, complexity and skill requirements for your operations considerably. One can take a simple photo of the point with geo-tagging on instead of having to capture data at every X meters etc.