Lane information traffic signs - important sources of information mostly ignored by advanced driver assistance systems

Lane information traffic signs (LITS's) specify an d spell out the arrangements of traffic lanes and provide important directional information at juncti ons and at other road locations for road users. The directional and lane information provided by LI TS's is particularly important when the directional signs and lane markings painted on the road are not visible for some reason. Although cars equipped with advanced driver assistance syste ms (ADAS's) run on the roads in growing numbers worldwide and some percentage of these ADAS 's provide automatic traffic sign recognition (TSR) functionality, as well, the LITS' s are mostly overlooked by these systems. This is partly due to the big number of the possible lane a rrangements and of the permitted vehicle directions, and therefore to the big number of the corresponding arrow- and stripe-based representations. A syntactic approach to generate, describe and recognise LITS's, particularly the LITS's used in Hungary, is presented in the paper. The approach can be incorporated in TSR systems that aim to recognise LITS's, as well. It r elies on directional image features; such features can be derived in many different ways including tem plate matching with generalized Gabor functions and from histograms of oriented gradients (HOG's).