From my observations in UK I can see that in the case of DTV the transmitted power levels are significantly different between the national DAB TV stations (BBC) and commercial/independent providers. 20KW to 9KW. DTV on commercial stations often drops over the digital cliff...pixalation and black out.
The DAB radio transmitted power levels in UK I cannot find but suspect its the same kind of ratio. With the BBC crap hanging in there most of the time and commercial drop out at the turn of a corner or down a gradient....a bit. ICE screen goes dumb as the ICE processor tries to recover above signal level threshold...no message on screen, just dead view. Changing station is usually an awkward event for most people I'd say....very unresponsive ICE system.
Its all about money...of course!