Guide and Informational Signs
Guide signs do not command; they orient. Green signs give destinations, distances and exits; blue signs point to services; brown signs mark recreation and cultural sites. The exam checks whether you can sort navigation information from regulation, and whether you can read the lane-use panels that appear on overhead expressway signs - the 'EXIT ONLY' panel that tells you a lane is committed.
The color families
Green: destination and distance signs, exit direction signs, route markers on guide signs, and mile markers. Overhead diagrammatic signs show which lane goes where before a split. Blue: motorist services - gas, food, lodging, hospitals (often marked 'H') and rest areas. Brown: parks, historic sites, museums and recreation areas, often on trapezoid-shaped signs. White-on-green street name signs identify cross streets. Route markers use shields: the red, white and blue Interstate shield, the white US highway shield.
Lane-use and exit panels
An 'EXIT ONLY' panel above a lane means that lane must exit. If you are in it, you either take the exit or change lanes while it is legal and safe. A yellow panel with a downward arrow over a lane means the lane is ending or committed to a turn. Diagrammatic signs draw the lanes as arrows so you can pick a lane a mile before the split rather than a hundred feet before it. Exit numbers and mile markers also let you count down to your exit instead of reacting to it.
Worked example
An overhead green sign shows three lanes; the right lane carries a yellow 'EXIT ONLY' panel. The driver wants to stay on the mainline. Correct action: move left early, checking mirrors and blind spot, and complete the lane change before the solid white line and gore area. The panel assigns that lane's mandatory destination, and crossing the gore or the solid line to escape is both illegal and dangerous.
Traps
Treating a blue or brown sign as a rule; waiting until the exit-only panel is overhead to change lanes; confusing a route marker with a destination; and misreading an arrow that points to a lane rather than to the exit ramp.