Earlier quoted context omitted.
With modern high powered CPU's, more detailed maps, and particle filters (which require all that cpu), dead reckoning has become much more viable. I suspect you could go hours driving round a city with the GPS and WiFi location turned off before losing your position - simple wheel speed, gyro and compass is sufficient for most stuff.
Hmmm. What about the sensors on my phone? For a while now I've wanted to know my realtime speed in the underground sections of the local rail/metro network. I suspect the most accurate measurements would be done using wideband SDR, iff I were able to acquire absolute position references for the signals I was seeing. Not likely, especially for something I might like to let others play with and/or generalize. Everywher…
With a particle filter and enough computation, that error can be eliminated after the fact. Ie. At the time you won't know where you are, but after you get out of the metro and the particle filter reconverged you'll know where you were with more accuracy at some point in the past.