If there is both a sign and lights, the lights apply.

Traffic lights precede signs in the hierarchy of authority (myndighetspyramiden).

Traffic lights:

A yellow light alone indicates the light is about to change to red.

Simultaneous red and yellow lights indicate the light is about to change to green. Simultaneous red and yellow lights indicate the light is about to change to green.

A yellow, flashing signal indicates that you must be careful and pay special attention when proceeding. A yellow, flashing signal indicates that you must be careful and pay special attention when proceeding.