Traffic Control Devices

You have just read a bit about why we need traffic control devices: lights, signs, and pavement markings. Now it’s time to review what those devices “tell” you. We won’t get into too much detail here. But when we present this information to you, you should be able to recall mostly all of the basics.

Traffic or road signs can be placed into one of a small number of categories. We’ll quickly go over them now:

Unique Shapes: A few very important traffic signs have unique shapes. Do you remember which ones and why? The STOP sign is the only octagon or eight-sided sign. The YIELD sign is the only one shaped like an upside-down triangle. These signs are critical to promoting crash prevention. Regardless of darkness or poor weather or even the poor condition of the face of those signs, you know what to do just by recognizing their shape. You’ll know who should stop and who should yield regardless of your direction of travel.


There are actually a couple more signs that are assigned unique shapes: The SCHOOL ZONE sign is shaped like the outline of a house. The NO PASSING ZONE sign is shaped like a sideways triangle – a pennant. They, of course, carry their own important messages. As you can see, these signs come in a variety of colors. Note the black on yellow school sign. Newer signs like this may come in black on fluorescent green. This brighter color is used to emphasize the importance of certain warnings by providing better visibility.

Regulatory: Regulatory signs tell you what to do (or not to do). Ignoring these signs is an invitation for a moving violation. While some may be in color, many display black printing on a white background. Regulatory signs direct, or regulate, the traffic flow. The most common examples you see are SPEED LIMIT signs and NO PASSING or NO PARKING signs. Add to that NO TURNS and the symbols that direct you to stay to the right of a center island.

Warning: In the context of traffic control devices, “warning” does not necessarily mean danger – unless you ignore the signs. Warning signs are diamond-shaped and typically show black on yellow (possibly a shade of fluorescent green on newer, higher level warning signs). You might see BUMP or SOFT SHOULDER (do not pull too far off the road when you see this sign). Many warning signs display symbols, mostly in the form of arrows. They “warn” you about the shape of the road ahead. Of course, you will typically see these signs in areas with winding roads or blind/sharp turns. Some warning signs simply alert you to the fact that there is a YIELD or STOP sign ahead – a testament to the importance of those two uniquely shaped signs.

What about black on orange diamonds you ask? You’ll recall, we hope, that black on orange warning signs alert you to the presence of a work zone. Why the difference? Consider hazards you may encounter in and around work zones that you might not see elsewhere:

  • Temporary change in road configuration marked by cones or barrels.
  • Construction workers moving around everywhere. Maybe someone will just walk out into your path forgetting that they are not just in a work zone but in a “driving zone.”
  • Heavy equipment moving around you from every direction dropping gravel or other material, kicking up dust clouds, or obstructing your view.
  • Reduced speed limits because of road conditions or changes in the configuration.
  • Flaggers stationed to stop you where you are not accustomed to stopping.
  • Multiple drivers operating on a road that may be poorly marked and has a new configuration. This new route gets even more difficult to navigate at night or in poor visibility conditions. That does not matter. You are responsible to practice the utmost care when driving in these work zones.

Informational: These signs guide or inform you and come in a wide variety of shapes and colors. Blue and white signs typically indicate services (such as the location of gas stations or even hospitals). Green and white signs provide direction to drivers. Think of highway exits and signs that indicate how far away your destination might be. Brown and white signs may tell you about the location of historic sites or other points of interest.

And we have route markers. Depending on the kind of road you are driving on, the signs will be different. You’ll see national highway markers or state road markers. You may even have local route markers. While you’re at it, don’t forget those long milepost markers. They play more of an important role than you think. In today’s day and age of smartphones, you can break down almost anywhere and place a call for help. The same goes for emergencies. But how do you answer the question, “Where exactly are you?”

Telling the EMTs you’re on Highway 55 may not help in a life and death situation if Highway 55 is one hundred miles long. Milepost markers enable you to report your precise location – or at least fairly exact – if you pay attention as you pass those markers. If you can provide the number of the marker you are close to or just passed, you can get help much more quickly. By the way, why the name milepost markers? They are, of course, placed a mile apart along the highway. The number on the marker indicates how far that particular marker is away from the point where the highway crosses the state line.

Traffic Lights: We have mentioned traffic lights a bit already, and you’ll read more about them as you progress through the course.  For now, suffice it to say that a red light (steady or flashing) indicates stop. By the way, red lights are not just found on those multi lamp traffic signals. If you come upon a single red light, probably flashing on a light pole, it carries the same weight as a stop sign.

Yellow indicates that a traffic signal is about to turn red. Yellow on its own means proceed if it is safe to do so. Again, you can find single flashing yellow lights at intersections. Think of them as yield signs.

Green means go – after you have determined it is safe to do so. Never move forward at a green light unless you are sure your path is clear.

More recently, we see the addition of lighted arrows at intersections. Just remember that the colors on the arrows basically mean the same thing as they do on the standard lights; now, though, you must also consider the direction of the arrows. The message sent by the color of the arrow pertains only to the direction in which it is pointing.

Finally, consider lane markers, which you are more likely to see on freeways. These are lighted X’s that inform drivers about the availability of a travel lane. A green X over a lane indicates it is open for travel. A yellow X indicates the light is about to turn red – that lane is about to close. A red X, of course, means the lane is closed. Do not drive in it. Lanes can close for any number of reasons: stalled vehicles or accidents, an obstruction in the road, or maintenance work. Never wait until the last minute to exit a lane displaying a yellow or red X overhead. Change to an open lane as soon as it is safe to do so and remember to signal well before you move.

A quick fun fact: “Stop is on top.” This is a great way to remember that, on a standard traffic signal, the top to bottom order of colors is red over yellow over green.

Pavement Markings: Pavement markings are painted on the streets and roads. They are as important as signs and lights – and they should be. You’ll see lane markers and crosswalk markers. You’ll also see stop lines and parking space markers. And don’t ignore painted curbs if you see them. We will mention these markings at various places throughout the course. You should already know what these markings tell you. Right now, we’ll present the basics and most important:

  • In general, you do not pass over a solid line.
  • You may pass over broken lines when conditions are appropriate: there are only broken lines painted on the road or, with a combination of solid and broken, the broken line is on your side of the road.
  • White painted lines usually indicate “same direction” travel.
  • Yellow lines indicate that traffic on opposite sides of the line moves in opposite directions.
  • A solid white line along the right side of a road typically indicates the right edge of the road before you hit the shoulder.
  • A solid yellow line along the left edge of the road indicates the edge of the road on one way streets or divided highways.
  • Yellow painted grid or diagonal patterns indicate places you should not park. Treat those areas as if a physical island is there.
  • Blue parking space lines are associated with spaces accessible to disabled persons. If you have no placard or disabled plate on your vehicle, you’ll incur a hefty fine for parking in these marked spaces. There is no such thing as “I was parked just for a minute.”
  • White stop lines indicate where to stop at a red light, stop sign, or railroad crossing. These lines are not friendly suggestions. Pulling up too close to one or stopping past it can certainly make other drivers wonder if you plan to even stop at all.
  • Soon, you will read about painted arrows that you will see in turning lanes. These arrows indicate which lane allows you to turn or travel in which direction.
  • You can actually see words painted on the road: STOP AHEAD is a common use for this type of marking.
  • You may come across curbs that are painted yellow.
  • While these aren’t painted on the pavement, red reflectors are extremely important for you to know about. Any time you see a red reflector as you drive along a road, it indicates you are going the wrong way! Exit that road immediately. If you see one along an access ramp, it means the same thing. Seeing red means you are exiting onto an on ramp or entering the highway from an off ramp!

And now for some more specialized pavement markings:

  • White painted diamonds signify HOV (High Occupancy Vehicle) lanes. Travel in these lanes is restricted during rush hours on major roads. This is to encourage people to carpool by allowing access only to vehicles carrying two or more individuals, including the driver.
  • Crosswalks are marked with solid white lines or pattern of lines that are perpendicular or diagonal.
  • Exclusive bicycle lanes are, of course, narrower than standard travel lanes. They’ll display the outline of a bicycle and a solid white arrow.
  • Shared-use lanes indicate that both bicyclists and motorists can use the lane. You will see the outline of a bicycle below a set of “sharrows.” These are sets of angled lines that resemble arrowheads.

Special Painted Line and Arrow Combinations

A bit earlier, we briefly mentioned turning lanes. You will read more about them later on. Just know that these turning lanes are one of a few combinations of painted lines and painted arrows that have specific functions and purposes. In the case of turning lanes, arrows painted on the pavement indicate the direction in which you can turn if your vehicle is in that lane. You might also see the word “only” painted just below the stem of the arrow. You will typically see solid lines that delineate the turning lanes. Those lines not only show which lane is which and where you can turn, but they also indicate that you cannot cross over them to pass or change lanes. Here are a few more line and arrow combinations you should know:

Turning Lane, Multi-Directional: Some turning lanes will allow turning from that lane in more than one direction. Typically it will be straight and right or straight and left or left and right but not straight. You will, of course see painted arrows with two arrowheads pointing in the appropriate directions.

Two-Way Turn Lane: On a multi-lane roadway, usually in a business district, you will see a two way turn lane. This is a center lane marked by double yellow lines on each side of the lane. The outside lines are solid and separate the center two-way turn lane from the regular travel lanes. Both inner sets of yellow lines are broken. You will also see large painted curved arrows pointing left from both directions of travel. Two-way turn lanes are NOT travel lanes. They are used solely for drivers who want to slow down and then make a left turn in a typically busy area. Never drive in such a lane unless you are preparing for a left turn. Be aware also that another driver making a left from his or her direction could move into the lane when you do, so be on your guard. Signal to enter the lane and signal again to make a safe turn off of the roadway. If you plan to turn onto a roadway that contains a two-way turn lane, don’t use that lane for travel. Get into a regular travel lane as soon as possible. Finally, NEVER use a two-way turn lane to pass another vehicle.

Reversible Lane: Reversible lanes are found on highways and are used to facilitate the flow of traffic during rush hour. These lanes have the same painted yellow double line pattern as do two-way turn lanes – solid yellow closest to the other travel lanes and broken yellow closest to the reversible lane. You will also see a double-headed arrow painted along the length of the lane. The direction of travel in a reversible lane changes based on the time of day. The lane will be open to vehicles heading towards a city or other business heavy area in the mornings. In the evening, traffic in that lane will flow away from the city.

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