Warning Signs and Roadway Alignment
Warning signs alert you to a change ahead: a curve, a hill, a merge, or a crossing. Minnesota's exam asks you to read the symbol, adjust speed before the hazard, and distinguish warning signs from regulatory signs.
Core rules
- Warning signs are yellow diamonds with black symbols or words; a yellow rectangular plaque under a sign gives an advisory speed.
- Curve and turn signs show the direction of the bend; chevron signs mark the outside of a sharp curve and repeat through it.
- Winding Road, Hill, and Downgrade signs warn of alignment changes; Merge and Added Lane signs warn of traffic changes.
- An advisory speed is not a legal speed limit, but it is the speed at which the curve can be driven comfortably; entering faster risks loss of control.
- Warning signs do not change right-of-way. A Cross Road sign does not give you priority over traffic already at the intersection.
Worked example
You see a yellow diamond with a right curve arrow and a 35 mph advisory plaque, while your speedometer reads 55 mph. The correct response is to brake smoothly before the curve, not inside it, and to enter at or below 35 mph. The plaque is a warning based on curve geometry; if you wait until you feel the curve, you have already carried too much speed into it.
Traps
- Reading the advisory plaque as the legal limit and ignoring it because it is not posted by a police officer.
- Confusing a curve sign with a chevron: the curve sign comes first, the chevrons continue through the bend.
- Speeding up to pass before a lane-merge warning instead of merging at the safe point.
- Missing a Two-Way Traffic sign after leaving a divided highway.