What does a curved arrow and the word ONLY marking a lane indicate?

The marking of a curved arrow accompanied by the word "ONLY" indicates that a driver is permitted to turn exclusively in the direction of the arrow. This guidance is crucial for ensuring smooth traffic flow and preventing confusion at intersections. For example, if the arrow points to the right, drivers in that lane must make a right turn; they cannot go straight or turn left. This helps to organize traffic patterns and enhances safety by clearly indicating the required action for vehicles in that lane. It is important for drivers to be attentive to such markings to avoid violations and potential accidents.