Width Mode
Note
This is the Width tile in the Edit palette of the Meta Road editor mode (see The Meta Road Editor Mode).

Width Mode edits the width of a Road Lane along the road. You edit the width curve just like a spline: set any shape, add/delete nodes, and edit tangents.

Selection
In the Details panel, the Selection group edits the selected Width Key:

See also
Road Lanes — the lanes whose width you edit here.
Section Mode — add, remove and configure lanes and sections.
Offset Mode — the other curve-editor sub-mode, for the center-line offset.