The sign you referred to is the Transition arrow - no oncoming traffic, 3-lane to the left, 1 lane diverted.

This traffic sign indicates a shift in the traffic flow on a multi-lane road. Specifically, it informs drivers that the road ahead has three lanes, with a designated lane for left turns or movements. One of the driving lanes will be diverted, meaning that traffic will be directed to continue in alternative lanes without oncoming traffic.

Drivers need to pay attention to this sign to adjust their lane positioning accordingly and ensure they follow the designated flow of traffic. It is particularly important for maintaining safety and avoiding collisions in areas where lane changes occur.

If you have any more specific questions or need clarity on related rules, feel free to ask!