Traffic Control: Signs, Traffic Lights, Lane-Use Lights, Pavement Markings and Traffic Officers

Written for aiforu2 as the source for a practice-test bank and the on-device tutor for the New York State Class D knowledge (written) test. The facts follow the official manual; the wording is ours.

Source: New York State Driver's Manual (MV-21), New York State Department of Motor Vehicles, chapter 4 "Traffic Control" (pp. 29–33).

Sign shapes and colors

Signs tell you the rules, warn of hazards, say where you are and how to get where you are going, and show services. Regulation signs are normally white rectangles with black letters or symbols, sometimes other shapes, sometimes with red. Warning signs are normally yellow diamonds with black letters or symbols. Destination signs are green with white letters. Service signs are blue with white letters or symbols. Work area signs are orange with black. Route signs vary: the shape tells you whether it is a state, U.S. or interstate route. The written test asks about signs.

Regulation signs

• STOP (red with white letters): come to a full stop, yield to vehicles and pedestrians in or heading toward the intersection, and go when safe. Stop before the stop line if there is one; if not, before the crosswalk; if neither, before the intersection at the nearest point that gives a view of the cross traffic.
• YIELD (red and white with red letters): slow down as you reach the intersection, prepare to stop and give the right-of-way to vehicles and pedestrians in or heading toward it; come to a full stop if traffic requires.
• Other regulation signs (white with black and/or red): traffic direction, lane use, turns, speed, parking and other rules. A red circle with a slash over a symbol means the action is not allowed or the vehicle is restricted; white rectangles with black or red letters flag special rules.

Warning, work area, route and service signs

A warning sign means a hazardous location or a special rule is ahead; it may be joined with a yellow-and-black recommended speed sign advising a lower speed there. Work area signs (orange) mean people are working on or near the road and a flag person may control traffic; a work area speed limit as low as 25 mph may be posted, and even without one you must drive at reduced speed and always obey the flag person's signals. Destination signs show direction and distance; plan with a map and watch for them so you never stop or turn suddenly. Service signs show rest areas, gas, camping and medical facilities.

Traffic lights

Lights run red, yellow, green from top to bottom or left to right; some are single lights, steady or flashing, round or arrows. When the lights are out of service or malfunctioning, stop as you would at a STOP sign and continue by the right-of-way rules unless a traffic officer directs you.

• Steady red: stop and wait for green. A green arrow with the red lets you go only toward the arrow, only if the intersection is clear. You may turn right on a steady red after a full stop, yielding to oncoming traffic and pedestrians, and turn left on red from a one-way road onto another one-way road after a full stop and yielding, unless a NO TURN ON RED sign, another sign, a signal or a pavement marking prevents it. In New York City you may not turn on red unless a sign permits it, and a school bus carrying students may never turn right on red.
• Flashing red: the same as a STOP sign: stop, yield, go when safe.
• Red arrow: do not go in that direction until the red arrow goes off and a green light or arrow appears; no turn on red at a red arrow.
• Steady yellow: the light is about to turn red; be prepared to stop.
• Flashing yellow: drive with caution.
• Yellow arrow: the green arrow's protection is ending; if you mean to turn that way, be prepared to stop.
• Steady green: go, yielding to other traffic in the intersection as the law requires. Green arrow: go in the arrow's direction, still yielding to traffic at the intersection as required.

Lane-use control lights above the pavement say which lanes may be used when: steady red X, do not drive in this lane; steady yellow X, move out of the lane; flashing yellow X, the lane is only for a left turn; green arrow, the lane is open.

Pavement markings

Lines and symbols divide lanes, say when you may pass or change lanes, which lane to use for a turn, and where to stop.

• Edge lines: solid lines along the side show where the travel lane ends and the shoulder begins; crossing the edge line is illegal except when an officer or an official sign allows. An edge line that angles toward the center means the road narrows ahead.
• White lines separate lanes moving in the same direction; yellow lines separate traffic moving in opposite directions. There may be one or two lines, solid or broken.
• One broken line: you may pass or change lanes when safe without interfering with traffic.
• Solid line beside a broken line: on the solid side you may not pass or cross except to turn left into a driveway; on the broken side you may pass when safe.
• Double solid lines: no passing or lane changes; cross them only to turn left into or out of the highway (a driveway, or a U-turn).
• One solid line: you may pass or change lanes only when obstructions or traffic conditions make it necessary.
• Stop and crosswalk lines: at an intersection with a STOP sign, YIELD sign or light there may be a white stop line across the lane and/or two parallel lines forming a crosswalk. When a sign or light requires a stop, stop before the stop line if there is one, otherwise before the crosswalk. You stop at these lines only when a light, sign or officer requires it, or to yield to a pedestrian, in-line skater or scooter at a marked or unmarked crosswalk. A single stop line set back from the intersection leaves room for tractor-trailers, buses and trucks to turn: stop before it.
• Arrows show which lanes to use for turns or going straight; be in the correct lane before the solid line separating the lanes.
• Diamond symbol: a lane reserved for buses, HOV vehicles such as carpools and vanpools, bicycles or other special vehicles; enter only when your vehicle meets the occupancy or other requirements during the posted hours. On city streets, where the solid white line beside a diamond lane is replaced by broken white, a non-HOV vehicle may enter the lane to turn right at the next intersection. Bus and HOV lanes exist to move the most important vehicles fastest on limited road space.

Traffic officers

Directions from a traffic officer override signs, signals and pavement markings: if an officer signals you to stop at a green light, stop; if the officer waves you through a red light or STOP sign, go. Those authorized to direct traffic include police officers, fire police, highway work area flag persons, school crossing persons and school bus drivers.

Practise this with New York Driver License questions

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