Ramp Advisory Speed With Hairpin Curve

Combined ramp warning showing a hairpin (180-degree) turn ahead with a 25 mph advisory speed.

Posted on freeway exit and entrance ramps, this combined plaque alerts drivers that the ramp ahead bends through a tight hairpin turn and that 25 mph is the safe negotiating speed under normal conditions. The advisory speed is determined by ball-bank or accelerometer testing, so slowing to the posted figure before entering the curve keeps tires within their friction limit and the vehicle inside its lane.

In the same family