It likely depends on the part of the state. There are famous parts of Virginia where the interstate is limited to 50mph and the police are some of the most productive in the country at giving tickets. These parts are connected to the parts that are 70mph, which causes people who did not notice the speed limit change to be ticketed. If they are so much as 1mph over 70mph when the speed limit changes to 50mph, it is a misdemeanor charge for reckless driving.