What do Metro-North and the Merritt Parkway have in common, I mean, aside from often crawling at a snail’s pace? Well, both seem to be hotbeds of unenforced safety rules. Anybody who has driven the parkway knows that its 1930s design cannot accommodate trucks, but they are there all the time. Tom Lombardo, a fellow board member on the Merritt Parkway Conservancy, recently conducted an unscientific survey to quantify the problem. In a single hour one weekday morning he logged 212 trucks, buses and commercial vehicles traveling in both directions on the highway.