[Talk-us] Gluing boundaries to roads

[Nathan Edgars II]

Nakor wrote:
At 2010-06-01 06:00, Lord-Castillo, Brett wrote:
>> I don't think I have encountered a situation where an administrative
>> boundary at the city level of higher follows a road (i.e. if the road
>> changes alignment, the boundary changes alignment).
>>
>Interesting. I worked on Michigan county boundaries and a lot of them
>are coincident with roads. I do not know if the boundary is defined by
>the road, or the road was built on the boundary, or the survey guys
>choose to make both coincident. Sometimes you will even see those
>boundaries (cities/townships for sure, counties to be verified) follow
>highway ramps.

Boundaries generally follow lot lines. So do roads, especially older
ones, so they don't split lots in half. In Michigan and most of the
US, most original lots and county lines were based on the Public Land
Survey System grid. So if the road is widened or realigned so that its
centerline is no longer exactly on the grid, the county line does not
move with it.

More recent municpal boundary changes may be from annexing individual
lots. In this case, the edge of the lot is not the centerline of the
road or even the edge of the pavement; it is the edge of the
right-of-way. So these boundaries do not actually follow ramps, but
instead follow the usually-parallel right-of-way line.

In the parts of the US that do not use the PLSS, older boundaries are
sometimes defined by reference to roads. But it is very likely that
this legally refers to the state of the road at that time, not to the
current alignment. Pages 28 and 31 of
http://web.archive.org/web/20031206194418/http://www.state.nj.us/transportation/refdata/sldiag/viewindx.pdf
illustrate this rather well.