Wiktionary
lengthsman
n. Someone who cares for a particular stretch of canal, railway, or road.
Wikipedia
Lengthsman
The term Lengthsman, coined in the 1800s, originally referred to someone who kept a "length" of road neat and tidy, but lengthsmen were used on canals and railways from the beginnings of both. On roads, lengthsmen were responsible for a few miles between adjacent villages and sometimes their duties encompassed the village itself. Employed by local parish councils, their job was, inter alia, to keep grass and weeds down in the verge, keep drainage ditches clear, and sometimes repair fences. Litter, such as it was in those times, was collected and even wild flowers were tended to.