Should "doughnut tires" be made illegal on the road?

One Saturday afternoon, i was running lasar radar on a four lane highway. i noticed an older model Buick LeSabre big car come rolling down the road with not one, not two, but four doughnut tires on this big, heavy automobile. it was a site to see. the auto was traveling way below the posted speed limit, so curiosity got the best of me and i pulled the car over. the driver had a drivers license from Mexico and i asked him if he thought his car was safe to drive on the open road. all he said was “si”. this was the only word he said throughout our one-way conversation. i looked in my traffic lawbook for a violation, but could not find one, involving doughnut tires. Question: was having four doughnut tires on a heavy vehicle, really safe for the road? i sent him on his way and all he said was “si”.