[valiant67]

Do you know if the front brakes have ABS or just the rears?

 

[Bob Lincoln]

Warped rotors. I had this happen in my 84 Daytona, it would just about shake apart when coming off the highway, but smooth at lower speeds. Changed pads and rotors and it's rock-steady under all conditions.

 

[valiant67]

I agree, it probably is the rotors but a missing ABS tone ring tooth or a stripped and loose caliper hold down bolt could be other less common items. The stripped caliper bolt got me on the 1999 Dakota which used a similar setup to your 2001.