The sign you are referring to is known as "Vehicles with water-polluting cargo to the left."

This sign indicates that vehicles carrying cargo that can pollute water bodies (such as chemicals, oils, or other hazardous materials) must take the left route or lane at the upcoming intersection or junction. This regulation is in place to minimize the risk of water pollution and to protect the environment, particularly near bodies of water.

Drivers must be vigilant when they see this sign and ensure that they follow the designated route to comply with safety regulations concerning hazardous materials. It’s also crucial for all drivers to be aware of their surroundings and the potential hazards associated with transporting such cargo.