Three com. petroleum road or industrial bitumens were modified by addn. of blends of rubber fines or expanded polystyrene waste with com. secondary petroleum bitumens at 250 degrees C for 90-120 min or at 250 degrees C for 360-480 min, resp., to improve bitumen properties (softening temp., ductility, penetration, dispersion stability) and utilize the plastics waste. The best properties showed the mixt. of the soft road bitumen (80%), rubber fine (7%) and clarified catalytic cracking oil or furfurol ext. (13%) and the mixt. of the brittle industrial bitumen (30%), expanded polystyrene waste (31.5%) and phenolic residue (38.5%).