In a direct mode two-way radio frequency communications system having a plurality of direct mode traffic channels, a first direct mode subscriber unit (DMSU) monitors a preconfigured direct mode control channel (DMCC), the DMCC being a channel that is monitored by all DMSUs that are idle in the system, and which is time divided into slots including traffic channel status slots (TCSSs), each TCSS associated with another physical direct mode traffic channel (DMTC) in the communication system. Responsive to detecting a request to initiate a new call, the DMSU selects a first DMTC on which to transmit the call, transmits during the next TCSS of the DMCC associated with the selected DMTC a header indicating the first DMSU's intention to transmit a new call on the selected DMTC, and subsequently switches to the selected DMTC and transmits the new call.