There is some use still by truckers to check for "smokey" reports, but they also have mobile online capabilities to use the web and cell phones.
The majority of use is by the "skippers", or those who operate base stations with hi-gain directional antenna beams and running linear amps to shoot "skip", where their signals can travel hundreds and even thousands of miles. One of the most active channels during skip time is Ch 6. It is not unheard of to hear signals on that channel during skip of conversations taking place between California and Maine and be as clear as if they were in the same location.
As to regular use by average citizens, there are far better alternatives like license free VHF hand held radios with ranges up to a mile or so. Most uses of these VHF license free bands are by hunters and campers, even tourists traveling in groups and will use them to communicate while on the road.
The CB band is still a useful piece of the spectrum. As far as I know, fire departments and police stations still monitor the emergency channel 9. Their communication systems have built in CB band capability so they can monitor and respond to any of the CB channels besides just Ch 9.