The canine, a 3-year-old beagle/chow mix named Harley, had escaped earlier from his backyard, which is just a block from I-17.
"Our gate doesn't close all the way. I put a trash can in front of it so he wouldn't slip out, and he still slipped out," owner Maddie Justus told KSAZ.
Highway traffic footage showed drivers slowing to pass Harley as he weaved between the lanes.
A man in a pickup truck was eventually able to grab the pup and handed him to officials on the other side of the median, who took him home to an anxious Justus.
"He's very lucky to be home, and I hope he knows that now," she said.