A method of discriminating between road markings of at least two colors, comprises: capturing an image of a road and at least one road marking with a monochrome camera having a first color response in a first area of a field of view of the camera and a second color response in the second area of the field of view; and determining the change in intensity of the captured image of the road marking between the first and second areas. Apparatus for discriminating between road markings is also disclosed.