DRIVING SOUTHBOUND ON TX SH 123 IN OUTSIDE LANE. SUDDENLY, MY TRUCK FELT LIKE IT WAS NUDGED FROM BEHIND, LIFTED UP AND WENT INTO A BACKWARDS SLIDE ACROSS 3 LANES INTO THE OUTSIDE NORTHBOUND LANE. I WAS STRUCK THERE BY A CHEVY ASTRO VAN, AND PUSHED OFF THE ROAD INTO THE BARDITCH. BOTH VEHICLES WERE TOTATALED, BUT NO INJURIES. ONE DRIVER IN EACH VEHICLE, NO PASSENGERS IN EITHER. BOTH DRIVERS WORE SEAT BELTS. HER AIRBAG DEPLOYED, BUT MINE DID NOT, SINCE I WAS HEADED BACKWARDS. UPON INSPECTION, BOTH REAR TIRES WERE BLOWN OUT ON MY TRUCK.( DOT NUMBER: JROM184303 TIRE SIZE: P265/75R16 )