One thing I have found interesting during highways having their exits converted from sequential to mileage-based is that sometimes the exit sequence reverses direction following the renumbering. Whereas the sequential numbers may have risen from say, north-to-south or east-to-west, when they become mileage-based, the exits rise in the opposite direction. The only highway in Massachusetts that will have its exit sequence reverse direction is MA 128, the portion that didn't become part of Interstates 93 and 95 in the 1970's. Excluding the traffic circle and two intersections that had numbers, the exit sequence started at 12, rising as one goes west, and continued to 29 (and historically continued to 69 when MA 128's terminus was at the freeway junction between Interstate 93 and MA 3). Now the exits will start at 37, rise as one goes east, and continue to 55.