Mercedes-Benz E-Class Coupe Operator's Manual page 226

Driving systems
224
The warning vibration occurs earlier if:
you approach the outer lane marking on a
R
bend.
the road has very wide lanes, e.g. a high-
R
way.
the system recognizes solid lane markings.
R
The warning vibration occurs later if:
the road has narrow lanes.
R
you cut the corner on a bend.
R