Garmin's nuvi 3490 LMT model - the "T" stands for traffic - will be fed constant traffic updates from NAVTEQ, with the cooperation of participating HD Radio operators. As Chicago-based NAVTEQ explains it:

"NAVTEQ can now deliver Traffic updates approximately every 30 seconds over 270,000 miles of the HD Radio(TM) broadcasting system across the United States. The ultra-rich transmission is 4 - 10 times faster than other traffic services making this the world's most extensive and fastest traffic service a consumer can find. The enabled technology is given that NAVTEQ Traffic is now transmitted over a wider radio frequency spectrum broadcasted over 3,400 HD Radio towers."

The HD Radio-powered traffic is part of the high-end Garmin nuvi LMT, and may also work with some other nuvi devices, using the after-market Garmin GTM 60 adapter.