That image is a pretty good approximation of CB range as well, looks like about 20 feet, depending.
CB range can actually be 3 to 20 miles , based on radio and terrain. Most important is antenna and SWR. If you mount your antenna to a metal , reflective, vehicle, you get what you get.
How to Install a CB Antenna - https://www.wearecb.com/how-to-install-a-cb-antenna.html#:~:text=The%20best%20place%20for%20your,going%20away%20from%20the%20vehicle.