Warning Signs
Warning signs alert you to a condition ahead so you can adjust speed and position. The Florida test asks you to match a yellow sign to its hazard and to distinguish an advance warning from a rule that is already in force.
The yellow diamond family
Most warning signs are yellow diamonds with black symbols and are placed in advance of the condition, commonly several hundred feet before it in urban areas and farther out on rural roads. Core examples: curve and reverse curve, crossroad, side road, T-intersection, signal ahead, stop ahead, yield ahead, merge, lane ends, divided highway begins or ends, two-way traffic, hill, narrow bridge, low clearance, pavement ends, slippery when wet, deer crossing and pedestrian crossing.
Plaques and chevrons
A yellow plaque with black numerals under a curve sign is an advisory speed, not a posted limit. Chevron alignment signs (yellow rectangles with a black chevron) are placed through the curve itself to show direction; they do not replace the curve warning. Object markers use yellow-and-black or red-and-white diagonal stripes to mark a hazard at the edge of the road.
Worked example
You see a winding-road diamond with a 35 MPH plaque on a road posted 55. The legal maximum remains 55, but 35 is the recommended speed for the curve under normal conditions. If the test asks 'what does the plaque mean?', the answer is advisory speed. If it asks 'what is the speed limit?', the answer is 55. In rain or at night, the safe speed may be lower than 35.
Traps that cost marks
Students lose marks by calling yellow signs regulatory. Yellow means warning, not law. Do not confuse the inverted triangle YIELD with a warning triangle, or a 'lane ends' sign with a 'merge' sign: lane ends means your lane disappears. 'Slippery when wet' applies when the road is wet, not only in rain. A deer-crossing sign does not mean deer are present at that moment, and a low-clearance sign gives a measurement in feet and inches that you must compare with your vehicle height.