You're driving down a local road on your way back from the grocery store when you notice a cop parked up ahead. You quickly glance at your speedometer: 45 mph. You panic. You can't remember the speed limit on this road. It's wide and divided so you feel like it should be 45 but it's one of those roads that local governments love to limit to a crawling 35 to catch out-of-towners unaware. You are just waiting to see the lights until you see a speed limit sign: 45 mph. You relax your grip on the wheel and slouch back into the seat letting out a sigh of relief.
And then you get lit up.
Incredulous, you ask the officer why you were pulled over for going exactly 45 in a 45. He responds with, "I felt like that was too fast." and writes you a ticket. That can't be legal can it? It can, and Jalopnik's David Tracy learned this the hard way.
Tracy was out and about on a Michigan night in his Moab-conquering Jeep Cherokee with a thin blanket of snow on the ground when he was pulled over and ticketed for going the speed limit. The reason this is perfectly legal is what is called the "Basic speed law." Plainly, the law is similar to the more common "Too fast for conditions" laws that allow an officer to determine if your speed, whether above the limit or not, is too fast to safely drive in whatever road conditions are present.
While usually only invoked when there is an accident or a car is clearly skidding or otherwise out of control, technically it is a judgement call by the officer. Tracy was able to fight the ticket and get it reduced to a fine with no points on his license by arguing that without any accident or loss of control, the charge was excessive. But even that reduction took an appeal and a lawyer to get past the "he said she said" stage where the cops win 10 out of 10 times.
I personally have been stopped for going the customary 4.9 mph over the limit in Georgia because there was a light fog that morning, and was only spared a ticket when I was able to convince the officer that my incredibly low car and fog lights meant that I was able to see right under the slowly lifting haze.
I got lucky, David Tracy did not. And the lesson is that you cannot count on changing a cop's mind about what is and isn't a safe speed. So, in conditions that could reasonably be a hazard, even when you and your vehicle are perfectly equipped to handle such an event, maybe give the cop a respectful 5 under as you go past.