Montana Department of Transportation

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Montana Traveler Information

Driving a Motor Vehicle

General Rules:

  1. Approach the roundabout as you would a typical four-way intersection. Be in the right approach lane if you intend to turn right, be in the left approach lane if you intend on making a left or U-turn, and any approach lane is OK if you are proceeding straight.
  2. Upon approaching the roundabout, stay to the right of the splitter island and SLOW DOWN to 10-15 mph.
  3. Watch for bicyclists and allow for them to merge into the entry lane.
  4. Watch for and yield to pedestrians in the crosswalk or waiting to cross.
  5. YIELD to traffic already in the roundabout.
  6. Once you’re in the roundabout, do not stop except to avoid a collision; you have the right-of-way over entering traffic. Always keep to the right of the central island and travel in a counterclockwise direction. Maintain a slow speed and DO NOT PASS other vehicles.
  7. Look for your street, use your right-turn signal and exit the roundabout.
  8. As you exit the roundabout, watch for and yield to pedestrians and bicyclists.

When Turning Right:

  1. Use only the right-hand approach lane, unless otherwise posted.
  2. Keep to the outside of the circulatory roadway while driving in the roundabout.
  3. If there are multiple exit lanes, use the right-hand exit lane.

view animated example
right turn from a roundabout


When Going Straight Ahead:

  1. Use either approach lane, unless otherwise posted.
  2. Maintain your position relative to other vehicles. Stay to the inside of the circulatory roadway if you entered from the left approach lane, or stay to the outside if you entered from the right approach lane.
  3. As you exit the roundabout, look out for vehicles traveling on the outside of the circulatory roadway that may continue to circulate around the roundabout.

view animated example
Going Straight in a roundabout


When Turning Left or Making a U-Turn:

  1. Use only the left-hand approach lane, unless otherwise posted.
  2. Maintain your position relative to other vehicles. Stay to the inside of the circulatory roadway until you are ready to exit.
  3. As you exit the roundabout, look out for vehicles traveling on the outside of the circulatory roadway that may continue to circulate around the roundabout.

view animated example
left or U-turn from a roundabout