Work Zone and Temporary Traffic Control Signs
Work zones change the rules temporarily, and the exam checks that you recognize temporary traffic control, obey the people running it, and reduce speed at the advance warning rather than inside the work.
Parts of a temporary traffic control zone
A work zone has four parts: advance warning area, transition area, activity area and termination area. Orange signs mark all of it - orange is reserved for construction and maintenance, so an orange diamond is never a permanent hazard warning. The taper is the diagonal line of cones, drums or barrels that shifts traffic out of the closed lane. Flagger stations use a symbol sign plus a FLAGGER AHEAD plaque, and a flagger's directions override signs, signals and markings.
Tapers, devices and speed
Merging taper length depends on speed and lateral shift. At 40 mph and below, the taper is roughly the shift width multiplied by the speed in mph; above 45 mph the length grows with the square of the speed, which is why freeway tapers look so long. Channelizing devices include cones, drums, barricades and temporary raised islands. A reduced speed limit inside a work zone is regulatory when posted on a white sign.
Colorado rules
Colorado provides for doubled speeding fines in work zones when workers are present, and the move-over law requires you to change lanes or slow substantially for stationary emergency, tow and maintenance vehicles displaying lights. END ROAD WORK appears only at the true end of the activity area, sometimes miles past the last cone.
Worked example
You meet ROAD WORK 1 MILE, then a posted 45 mph where the normal limit is 65, then an arrow board closing the right lane. The 45 is regulatory because it is a white speed limit sign, so exceeding it is speeding rather than an advisory issue, and the fine can be doubled if workers are present.
Traps
Slowing only when you reach the cones instead of at the advance warning sign. Disobeying a flagger's SLOW paddle. Assuming the work zone limit ends at the last cone rather than at END ROAD WORK. Ignoring the move-over law because no police vehicle is present.