CHI85LA089

At 1215 EST, a ground vehicle operator (S-1) rprtd that the braking action was poor on the rwys & taxiways (twys). In the next 9 min, 5 snow plows were cleared onto twys a & e. a short time later, the plt of N58PC was cleared to taxi fm the general aviation ramp to rwy 26L, but he was not issued info concerning braking action or other traffic. While he was taxiing on twy a, a snow plow on twy e converged from the plt's left. The snow plow operator was windrowing already plowed snow. He stayed to the left as he went onto twy a & was traveling ahead of N58PC. The plt of N58PC alerted groundcontrol psnl of the snow plow's psn & steered his acft to the rgt. The snow plow operator then started to make a 180 degrgt turn on the twy, but stopped when he saw the acft. The plt tried to avoid a collision, but his left wing hit the snow plow. The snow plow operator said there was a blind area to the rgt side of his cab which may have attributed to his lack of vision. The tower controller was responsible for both acft & vehicular traffic per letter of agreement.