HD Datacasting Begins In Earnest

Clear Channel recently announced it’s started broadcasting traffic data information on 48 HD Radio-equipped stations around the country. It’s the first use of a digital radio signal for the delivery of content wholly separate from main program audio; the “Total Traffic Network” is a wholly-owned subsidiary of Clear Channel. It’s unclear how this service will compete with Clear Channel’s datacasting partnership with Microsoft, which also seeks to provide traffic information.
How does it work? That’s not quite clear: Clear Channel’s press release notes that Total Traffic information will require “specially equipped receivers available by the end of this year”; otherwise you need a portable GPS unit and an annual ~$60 subscription to get access, or a new car from BMW or Mini with built-in GPS onboard.
As for the content itself, the HD content of Total Traffic appears to replicate information already delivered via preexisting analog-based digital data subcarrier transmission systems (which also require specially equipped receivers to utilize). Thus while the launch of commercial data delivery via HD is notable, the actual data delivered does not represent any great leap forward.