Signs, signals and markings in South Dakota

By the end of this topic you can

• You can recognize sign types by shape and color.
• You can explain what each steady, flashing and arrow signal means.
• You can act correctly at a dark or broken traffic signal.
• You can read center lines and lane markings and know when passing is allowed.
• You can respond to railroad crossing signs and signals.

What you need to know and understand

• A stop sign has eight sides and is red with white letters.
• A yield sign is a downward-pointing red and white triangle.
• Warning signs are usually yellow diamonds. Work zone signs are orange.
• A flashing red light means the same as a stop sign. A flashing yellow light means slow down and proceed with caution.
• A broken or completely dark signal: treat red or dark like a stop sign.
• A reflective orange triangle means the vehicle travels under 25 mph.
• Passing is allowed when the dashed yellow line is on your side.

Reading signs by shape and color

• Regulatory signs are white rectangles or special shapes with black, red or green letters. A red circle with a slash means the action is prohibited.
• Warning signs are yellow diamonds. School and pedestrian crossing signs may be fluorescent yellow.
• Work zone signs are orange. Speeding fines in work zones may be doubled.
• Guide signs are green or brown. Service signs are blue.
• The round yellow sign with an X and RR warns of a railroad crossing ahead. The white X-shaped crossbuck marks the crossing itself.
• A minimum speed sign means you must go at least that fast in normal conditions, or use another road.

Signals, arrows and beacons

A steady yellow means the light is about to turn red: stop if you safely can. A red arrow means no turn in that direction until it goes out. A yellow arrow means the protected green arrow is ending. A flashing yellow left arrow lets you turn after yielding to oncoming traffic and pedestrians.

A pedestrian hybrid beacon (PHB) has two red lenses above one yellow lens and stays dark until someone presses the button. It then shows yellow and red lights telling you to slow and stop while pedestrians cross mid-block. If any signal is broken, a green or yellow lets you proceed with caution, and a red or dark signal means stop as if at a stop sign.

Markings on the road

A double yellow center line means no passing in either direction. A dashed yellow line on your side means you may pass when it is safe. White dashed lines separate lanes going the same way. A shared center lane, edged by solid and dashed yellow lines, is for left turns from either direction. Stop at the stop line first if there is one, otherwise before the crosswalk.

Signs you may see only in South Dakota

White THINK signs, each on its own post, mark where a person died in a crash on a state highway. The program began in 1979 to remember victims and remind drivers about impaired driving, seat belts, speed and distraction. At railroad crossings, look for the blue Emergency Notification System sign with a phone number and a crossing number to report a stalled car or a crossing problem.

Common mistakes

• Treating a flashing red like a flashing yellow. Flashing red always means a full stop.
• Driving through a dark signal. Stop as you would at a stop sign.
• Passing on a solid line on your side because the road looks clear.
• Ignoring work zone limits when no workers are visible. The lower limit and higher fines can still apply.

Test yourself: Signs, signals and markings in South Dakota

Answer each question, then read the explanation. Questions come in a random order each time.

Go deeper

• Learning to Drive in South Dakota
• South Dakota 50-Hour Practice Log
• South Dakota Driving Test and When Driver’s Ed Waives It