You may think there’s no harm in going 5 or 10 mph over a posted speed limit. But based on state laws in Missouri and Illinois, you should probably think twice before speeding.

According to the Federal Highway Administration, posted speed limits “are those that are sign-posted along the road and are enforceable by law.” Anything above the posted speed limit is technically a violation. And it’s up to state legislatures to establish these speed limits for different types of roads.

With this in mind and with inspiration from KDVR, we wanted to learn more about speeding enforcement.

KDVR’s digital report dug deep into two questions: Could driving 5 miles per hour over the speed limit lead to a ticket? If not, how fast can someone go over the speed limit before being pulled over?

Illinois State Police Public Information Officer Christopher Watson offered this insight:

“The State of Illinois has what is called an absolute speed limit law. In essence, if you drive faster than the posted speed limit, you are in violation of the law and can be cited for the infraction accordingly.”

Illinois State Police also outlines policies for acting upon speeding violations in a department directives page. Under the “Speed Limit and Occupant Restraint” section, a document reads, In cases “ten or more mph above” the posted speed limit, “issuing a citation will be the standard enforcement procedure.”

Interpreting speeding laws in Illinois, it’s not likely you’ll be pulled over for going five miles over the speed limit compared to anything exceeding that, but it’s still against the law and could lead authorities to issue a ticket depending on the circumstance.

Revisiting KDVR’s report, one big consideration in setting a speed limit is the ability to stop in time in case of something unexpected. If you’re speeding, it could take longer for you to react and brake should the vehicles ahead of you suddenly stop.