I had a steer tire blowout on i84 in Oregon. I was pulling doubles and going 65mph when it happened. Keep on this gas if you have your wits about you when it happens. Just don't hit the brakes. All your weight will shift right to the rim where you lost the tire and you will wreck. It was a very violent experience and the truck was suddenly handling like it was on roller-skates in an ice rink. Mine was a brand new tractor with just 200 miles on it at the time of the incident. As soon as the blowout occurred my tractor immediately dropped to about 40mph, and from there I just let it coast for about a mile before the truck finally came to a stop. Number one rule DON'T HIT THE BRAKES.
I've always considered myself very fortunate to have randomly stumbled across a video online about steer tire blowouts and how to handle them. It was never taught in feeder school and had I not seen the video, I would not have properly reacted, because your gut instinct is to stop the vehicle as quick as possible when something like that happens.