R209

R209 / 1:Mc

Merge Lane diverts traffic into exactly one Driving Lane

Driving Lane accepts traffic from zero, one or many Merge Lane

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When a Merge Lane closes, the traffic must have a place to go. As a Merge Lane comes to a close, it diverts its traffic into a single adjacent Driving Lane. (If there are multiple outlets, this is a Split and not a Merge Lane).

A given Driving Lane may not be adjacent to any Merge Lanes or it could be adjacent to one or even two (on the left and right side). In this case, each side will probably be offset by some longitudinal distance. The normal case, though, is just one on the left or right side.

Formalization

Merge Lane.(Dest lane inside, Dest lane outside, Road segment) -> Driving Lane.(Inside division, Outside division, Road segment)

By sharing the Merge Lane.Road segment reference between R88, R83 and R90 we constrain the destination Driving Lane to be in the same Road Segment as that of the Merge Lane.

Constraint R83c

Merge Lane/R83/R80/R85/Driving Lane.Conduit == Merge Lane/R88/Driving Lane.Conduit