There are some areas with no operating local DABmultiplex - this means that there are no local commercial radio stations on DAB, and also no BBC services.
The provision of these multiplexes was intended to be provided by commercial operators, but there has been a recent DAB promotion dispute due to some radio stations wanting the BBC to operate the multiplexes.
It should be noted that the commercial operators may wish the BBC to do this, but the BBC would require approval of the BBC Trust and Ofcom, and of course the money would need to come from somewhere.
Here is a list of the areas concerned:
BBC Radio Cumbria
No plans for DAB service exist, currently on 95.6 FM, 96.1 FM and 104.1 FM.
BBC Radio York
Planed to be on the not-yet-operating North Yorkshire (North West) commercial radio multiplex, currently on 103.7 FM and 95.5 FM.
BBC Radio Lincolnshire
Planned to be on the not-yet-operating Lincolnshire commercial radio multiplex, currently on 94.9 FM and 104.7 FM.
BBC Radio Derby
Planned to be carried on the Derbyshire commercial radio multiplex, currently on 104.5 FM, 95.3 FM and 96 FM.
BBC Hereford & Worcester
To be carried on the Hereford and Worcester commercial radio multiplex, when operational. Analogue services on 104 FM and 94.7 FM.
BBC Radio Northampton
Will be carried on the Northamptonshire multiplex when operational, currently on 104.2 FM and 103.6 FM.
BBC Three Counties Radio
To be carried on the Herts, Beds+Bucks commercial multiplex when operational, current services on 95.5 FM, 103.8 FM and 104.5 FM.
BBC Radio Suffolk
No plans for DAB service to replace 95.5 FM and 104.6 FM
BBC Radio Surrey
To be carried on two commercial multiplexes, Guildford and Surrey+North Sussex, when operational, currently analogue on 104 FM and 104.6 FM.
BBC Radio Oxford
Planned for carriage on the Oxfordshire commercial multiplex, when operational, on 95.2 FM currently.
BBC Radio Gloucestershire
Planned to be carried on the Gloucestershire commercial multiplex, when operating. Currently broadcast on 104.7 FM and 1413 AM.
BBC Radio Somerset
No plans to supplement 95.5 FM and1566 AM currently.
No plans to add digital services to 93.2 FM and 1116 AM.
No plans to add digital services to 88.8 FM and 1026 MW.
BBC Radio Wales and BBC Radio Cymru
Operating on Cardiff+Newport and Swansea multiplexes, but both radio stations awaiting three commercial multiplexes to be operating: Mid+West Wales, NE Wales+Chester and North Wales to complete coverage.
Running six month DAB test service in addition to 93.1 FM and 792 MW.
I think you will now find the 2015 SWITCHOVER won't be happening until 2020 (AT THE EARLIEST). Quite rightly so with DAB / DAB + in such a mess and FM offering superior sound quality on some national stations in the evening and overnight