Common use frequencies for Citizens Band, or CB, radio start at frequency 26.96500, which is CB Channel 01 - Common Use, and end at Channel 40 - Common Use at frequency 27.40500 as of 2016. A full list of common use frequencies is listed at RadioReference.com.
Citizens Band, or CB, radio frequencies, are commonly used by radio hobbyists to broadcast short-range radio transmissions and by long-haul truck drivers to communicate traffic problems, directions and other relevant matters. It can be used for both personal and business purposes and does not require a license.
Citizens Band radio is a short-range radio communications system that operates in a selection of 40 channels within 27 MHz band. Created in 1948, CB radio was the only practical two-way radio system available to consumers for decades. Citizens Band radio became very popular in the 1970's but lost its appeal in the following decades with the appearance of the Family Radio Service.