Really? I would say trains, buses and cars are really common use cases for mobile data. Every second person I see is watching Youtube or playing around on the internet while they take public transport. It isn't biased data, there is an actual use case that it is presently failing.
These are typical results. I make networking equipment that has to deal with wireless connections. Our tests are as ideal as you can get without driving around for a tower and sitting under it (although we have done that, too). We're typically in an office, stationary. This means no tower hand-offs, and stable (relatively) conditions. Round-trip-times in the 20 sec range are not rare. I've even seen RTTs a minute long several times, and once saw even greater than 90sec.
What is really interesting is to watch the RTT while you run a speed test.
Faster travel meaning you are passing in and out of cells more often, and you are more likely to be passing through areas with bad coverage either for man-made geographical reasons (a steep embankment between you and most of the towers in range for instance) or because your route is more likely to take a straight-ish line that may pass through a pretty uninhabited area that is ether completely unserviced by the cell network or where the only tower(s) in range are some distance away. Also if you are travelling by bus (and to a certain extent by car) you are more likely travelling a shorter distance than if travelling by train so are less likely to be passing through areas that are badly served because there is no money in the networks serving the two local farmers as well as they serve a small town.
Trains also dampen the signal. Many German high speed trains have repeaters but those don't yet (hopefully!) work with UMTS. Cars and busses have admittedly the same problem but maybe to a lesser extent.
Cross Country trains (what was Virgin's bit of the rail franchises) are worse for this than anything else on the UK rail network. I'm told it is due to a combination of the materials in the construction of the carriage frame, and the anti-glare layer in the windows. If you are at the end of a carriage, signal strength/reliability seems to jump a bit when you are sat at a station and the doors are open.
Other trains don't seem nearly as bad. I'm not sure how much of that is due to different construction or (in the case of other modern(ish) rolling stock) anything like the repeaters you mention (though as all the franchise owners are cheap-arses I very much doubt that tech has been paid for by any of them!).
the area of each cell typically increases when you move out to sparsely populated areas with vast expanses of land. thereby, minimizing number of handovers (cell-to-cell) that might be happening.
Aye, but that is what creates the "distance from tower" problem of getting poor signal quality due to normal attenuation over distance and the larger number potential shadow/interference causing things between the tower and you.
There are a number of places where trains skip around at a goodly speed in what is probably a packed area by way of phone cells, so there will sometimes be a significant number of cell-to-cell hand-offs. Having said that, as I grew up (well, more-or-less) before mobile phones were common I'm still slightly impressed that the whole cell hand-over thing works at all mid-call at 80+mph so maybe they are not much of an issue unless the destination cell is already saturated at the time.
