I don't drive 28 every day, but I have seen my share of either State Police or Wolfeboro's Finest in the 40 MPH zone on 28 just east of Springfield Pt Rd. They watch both ways, catching those coming up the hill accelerating to 55 well before the sign, or catching those coming over and down the hill who have not slowed down from 55.
As for driving the 55 speed limit portion, all else fails, use your cruise control.