Which color traffic sign is used for lanes designated for e-toll collection?

The correct answer is purple because this color is specifically used to indicate lanes or areas designated for electronic toll collection, or e-toll. Over recent years, transportation authorities have adopted purple signs to help drivers easily identify these lanes at toll plazas. The purpose of this color choice is to provide clear differentiation from other types of signs, ensuring that drivers looking for these lanes can do so without confusion.

Purple is distinct and is not commonly used for other traffic signs, which helps in making it immediately recognizable to motorists. This enhances both safety and efficiency in tolling operations, as drivers can make informed decisions about where to go without needing to read much text. Other colors, such as red, white, and yellow, serve different functions within traffic signage, like stopping or cautioning drivers, and do not pertain to electronic toll collection.