Just north of Dorchester on Hwy 289 (Preston Rd)
The speed limit drops from 70 to 55. If you miss the sign you are in for 15+ over the limit. They are watching and waiting to clock you as soon as you pass the 55 mile per hour sign. No warning, no grace. There are cops every where and I always see 1 to 3 cars pulled over at a time!
It is the same heading South from 56. People assume 70 since you are in the middle of no where.