The driver of this tractor-trailer was stopped by an AZDPS trooper on westbound Interstate 10 in Goodyear for operating an 18-wheeler with only 16 wheels. The driver explained they had hoped to make it to California to buy new tires.

 https://www.facebook.com/photo.php?fbid=525951392900988&set=a.220812323414898&type=3

In the comments, a lot of truckers are saying this chained up axel is fine, and if the trailer is empty, this isn't a problem