右左折禁止アメリカ合衆国

A turn prohibition prevents drivers from making a particular turn or change of direction indicated by a traffic sign.

It is commonly a circular sign with a red border showing a crossed or barred turning arrow. The arrow indicates the movement that is prohibited.

It prohibits drivers from turning left at the location or intersection to which the sign applies.

It prohibits drivers from turning right at the location or intersection to which the sign applies.

It prohibits drivers from turning around to travel in the opposite direction.

No. A prohibition sign identifies a movement that may not be made. A mandatory-direction sign identifies the direction or directions that must be followed.

No. A turn prohibition prevents a particular approach from turning into a road. A no-entry sign prohibits vehicles from entering the road from the direction where it is displayed.

No. A one-way rule controls the permitted direction along a road. A turn prohibition controls a particular movement at or near an intersection.

It may apply at the sign, at the next intersection or throughout a stated section. Drivers must follow the sign design and the rules of the country concerned.

Yes. An advance sign or supplementary distance panel may warn drivers that the prohibited turn is farther ahead.

Yes. A sign positioned above or clearly associated with one lane may apply only to drivers using that lane.

Yes. Drivers must choose the correct lane and follow one of the directions displayed by its legally binding arrows.

No. A green light permits traffic to proceed, but drivers must still respect turn prohibitions, lane arrows and other regulatory signs.

No. Drivers making another permitted movement must still follow traffic lights, priority signs and the ordinary rules concerning pedestrians, cyclists and other vehicles.

No. The applicable general, zonal or posted speed limit remains in force.

Yes, where local law requires it. Signal early enough to communicate your intention and stop signalling after completing the movement.

No. An indicator communicates an intention but cannot authorise a movement prohibited by a traffic sign.

Yes. A supplementary sign may allow cyclists or other specified road users to make a turn that remains prohibited for general traffic.

Public transport, taxis or other authorised vehicles may be exempted where a supplementary sign or local rule expressly permits the movement.

Not universally. Some countries treat these as separate prohibitions. Drivers must check whether a separate no-U-turn sign or general rule applies.

This depends on the exact legal scope of the sign. A sign applying specifically to the next intersection may not regulate an earlier property entrance, but another sign or road marking may still prohibit the movement.

No. Do not reverse through traffic or into an intersection to evade the sign. Continue along a permitted route and change direction later where it is legal and safe.

Follow the movement permitted from that lane. Do not turn suddenly across another lane or ignore the sign; continue and choose another legal route.

Yes. Properly placed temporary signs near roadworks, incidents or events must be obeyed.

Yes. Follow instructions from an authorised traffic officer even when they differ from the displayed turn prohibition.