Most truckers that are on the road use channel 19 to get in touch but ussually move to a different channel to talk to someone privatelly.
A CB radio is a Citizens Band Radio. It has 40 channels and is used for short distance communication. CB radios are mostly used in semi trucks so that they can communicate with other truckers, weigh stations, home base, and to find out the weather. A CB has different channels for different things while you are on the road. Channel 9 is for emergencies, channel 19 is a highway travelers monitor channel, you can get information about road construction, police blocks, and weather. Some of the features that a CB radio has are: Automatic noise limiters, a built in pa system or "bullhorn", Volume controls, and many microphone features.
The specific channels used on a Citizen Band (CB) radio can vary depending on the region and country. However, in the United States, channel 19 is often used for highway communication between truck drivers. Channel 9 is also commonly used for emergency and calling purposes. Other channels may be designated for specific uses such as truckers, off-road enthusiasts, or recreational users.
Used, about $40 - 50 is all you'll get out of it.
CB radio ch 9
channel 9
Channel 40 Frequency: 477.400 Simplex Highway Channel
Except for the UK most of the planet only allows use of 40 channels for CB. Big fines and all sort of trouble goes to those who modify CBs to operate outside the 40 channel limit. Frequencies above and below CB are used by other people who send Police around to those who do not respect the limits.
Channel 19 is the most commonly used for general talk, chatter, etc, throughout most of the US, although Channel 17 seems to be more popular for that purpose in California.
Truckers talk to each other on the move using the citizens' band radio. This is abbreviated CB radio. Every trucker has a nickname, and can warn others of hazards, such as traffic jams or bad weather.
To my experience, no, they are not required to have call signs. Most choose to have their CB signal advertised so they can keep in contact with other truckers on the road, but again, from what I am seeing, they do not have to. It is advisable that they do however, that they can coordinate with other people over the CB. Warn other of traffic conditions further up the road and render assistance as needed,
In most of the US, it's 19. In California, they like to run 17. A lot of truck drivers don't use their CB radio, so there's no guarantee you'll get a response. Plus, they're probably not all that interested in talking to you, anyhow.
Supposedly, they monitor Channel 9, but it's really rare to find police officers/police agencies which actually do. If a police officer is monitoring the CB radio, they're more likely to be monitoring Channel 19 than Channel 9.