The National Traffic System (NTS) is a nationwide network of amateur radio operators who relay messages called radiograms across the United States, Canada, and any country covered by a third-party traffic agreement. The American Radio Relay League (ARRL) and Radio Relay International (RRI) jointly develop and maintain the NTS under a Memorandum of Understanding.
The NTS relays radiograms through time-sequenced, tiered voice and CW traffic nets. In addition, the Digital Traffic Network facilitates forwarding radiograms so they can be moved to traffic nets serving the message recipient’s location.
Most of the radiograms NTS handles day to day are routine messages — birthday greetings, holiday wishes, and the like. That steady flow keeps the system running smoothly and operators sharp, so everything is ready to work when truly needed.
When disaster strikes, NTS supports the Amateur Radio Emergency Service (ARES), relaying emergency communications when normal channels are overwhelmed or unavailable. The most common of these are “health and welfare” messages — checks on people inside the affected area and reassurances sent out to family and friends elsewhere.