Come on. If you live in the DC area as your handle implies, you know that's bunk because of how traffic is enforced in the area.

2 reasons: precision and prerogative.

There's error inherent in the process that can't be compensated for, whether that's human or technical. Lasers and radar aren't 100% precise even when properly calibrated, and it's easy for the officer to make a mistake. Cops know this. Unless the officer is extremely bored or hasn't met their quota, no cop will waste their time on such a ticket, as there's a high likelihood of it being thrown out. It's a big reason why cops will often give 5-10 over as then there's no dispute of three person speeding.

Same thing with overweight bags. If you're over by a pound or so, they'll usually let it slide they as the scales aren't precise. Push 52-53 pounds and you're a lot more likely to get hit with the fee.

Enforcement varies. As I said before, no cop is going to write up 56 in a 55. You're right, technically they could. But it's not worth their time to do so as a ticket like that will be challenged, and if it's not outright thrown out, the revenue it brings is too low to not make it work it.

There are bigger fish fry, and that's what the focus is. MSP has already said in the Baltimore Sun that they generally don't pull people over unless they're doing at least 80 in a 65. They said there's plenty to keep them busy above that did they let the small potatoes go. They're going after the egregious violators.

Yes, I've been passed by cops while doing 85 and also passed sitting cops at that same speed. Knowing the policy, I consider myself fortunate I didn't get l busted in those incidents, but I know I might not be that lucky next time.

Also, there's the flow of traffic. If everyone's going 80-85, it's doubtful anyone's getting pulled over. They'll go after people doing 90+. At least in Maryland, of everyone's going that fast and you're doing the speed limit, you're going to get the ticket for inhibiting the flow of traffic.

So it should be with carry on bags. Most GAs have been around enough to know the rough size of a bag that should fit. Measuring every bag would slow boarding significantly, and that goes against their incentives you get that planes out on time. That should be looking out for the big violators, ones whose bags are obviously too big. We've all seen those bags where we wonder how a GA ever let that pass. But an inch or so either way? Come on, that's just being nitpicky, especially when other similar bags are being let thru.

Yes, the letter of the rule says one thing, and they're within their right to enforce it. But the whole reason such a rule is in place is to prevent people from bringing big bags on board. As long as they're reasonably close and similar to others, let them go. The intent was met. If it's way too big, have at them

There's nothing black and white about either of these situations.