Millions of British consumers that have invested in automotive navigation systems may find their usefulness impaired should a national FM analog radio sunset actually be implemented.

According to a report in the Telegraph.uk, real-time traffic information used in a variety of OEM auto satellite navigation systems relies on the use of RDS data transmitted over big-signal analog FM stations. None of those systems, estimated to number up to 3 million, currently include the ability to receive that data from a DAB signal. Should those FM signals go dark, as called for in current policy, those devices would be rendered useless in their ability to respond to real-time traffic conditions.

Among the possible options to avoid loss of service would be maintaining key FM transmission systems without audio modulation, or a government subsidized replacement program for the GPS navigation devices. Given the extraordinary austerity measures being called for by the current British government, neither alternative seems very palatable.

Digital Radio UK, a private industry group charged with advancing the DAB transition has reportedly responded to public awareness of the issue by calling a summit with automakers, regulators, and service providers to discuss the issue.