I saw the signs

I started the day with a jog. At 6:45am it was nice and cool and the humidity was low, but my head was still a little sleepy. As my mind started to awaken I noticed some unusual signs. The first one l had seen before, but never really thought about it. It has a picture of a runner and bicycle with a speed of 20km/h under it. As I shuffled I wondered what the sign was trying to tell me. Was it telling me to speed up to 20km/h or was it telling me not to exceed that speed?

The question didn't whirl around my head for too long as I was distracted by a truck that had a logo on it that said Dicks Pumping Service at this point I decided to put my head down and just run.