Q: When I try to stop in a short distance at highway speeds, my car jerks just before coming to a complete stop.

Whenever I am trying to make a short stop, from 30+mph, I feel a slight bump, as if I'm running over a small speed bump. The faster I go, and the quicker I try to stop, the harder the bump feels. I believe it's like a hard downshift from 2nd to 1st gear. I also get an ever so slighly rough upshift from 1st to 2nd gear, when compared to any other shift. Any where between 2nd and 4th gear is smooth, whether it be an upshift or downshift. It's just between 1st and 2nd gear when I feel it. At first, I pictured in my head the breaks biting down for a second whenever I felt the bump. But as I experimented, this is about as much as I could narrow it down.

My car has 193000 miles.
My car has an automatic transmission.