The peril of tearin' up jack

I remember Amos. He was one of Grandpa Joe's best friends, and lived just up the street. Often he would walk down to visit Joe and if one of us kids were out, he'd stop to shake our hand and say hi. I always thought that was pretty cool of him.
He had a phrase for when he was going some place in a hurry. He'd say he was "tearin' up jack". One day his tearin up jack cost him an extra ten minutes.
Amos was coming down the Lodge Freeway here in Detroit, hurrying to get home. Now, I don't know if other parts of these United States have such things, but on Detroit freeways many exits have turn around lanes at the top of the ramps which allowed you to make a U-turn without making a left turn onto the street where you exited. Maybe you wanted the street a couple blocks back, say, so this way you could loop around to it without making two left turns. It was thought to help traffic flow, I've always guessed.
But anyway, there was often an entrance to the freeway on the far service drive after the turnaround lane. If the street merited an exit it merited an entrance too, right? In this case, Amos was exiting at Forest Avenue but wanted to double back to Warren, which was two streets north. So he intended to take the turnaround lane at Forest and double back to Warren.
"Here I am headin' south on the Lodge tearin' up jack', Amos explained, "And I fly up the ramp and take the turnaround tearin' up jack, and I get on the far service drive and run right down the entrance ramp onto the northbound Lodge." Yep. In his hurry to get home, Amos had become for an instant absent minded and tore up jack right back onto the freeway.
That's the peril of tearin' up jack. You can forget where you're supposed to go.