Buses can operate through difficult terrain in rural and semi-rural areas, trains can't.
Eh?? I was at Swansea stations at late O'Clock last night, and just about the only train running was on the Shrewsbury line, which I would consider to be difficult terrain and distinctly rural. Other lines through rural areas of difficult terrain include those to Whitby, Mallaig, Wick and Blaenau Ffestiniog.
Fair point. I was thinking of routes where there never has been a railway, like Fishguard - Cardigan - Aberaeron - Aberystwyth, when I wrote that. The rural nature means the cost of getting through the difficult terrain (lots of valleys to cross, rather than running along them as most of Carmarthen-Aberystwyth, for example, did) would never be justified.
Buses don't grind to a halt when leaves fall off trees
Nor do trains, I think. Isn't the problem with leaves that the train cannot stop moving (it slides) or cannot start moving (wheelspin)?? Neither are exactly decribed by the phrase 'grind to a halt'.
nor are they subject to massive delays when a (traffic) signal fails
What if the traffic signal is stuck on red? Doesn't happen very often, but how long does the driver wait before he/she knows the light is broken and ignores it. This seems mostly to be a problem with temporary lights at roadworks, which have caused my family delays (maybe not 'massive', I suppose) when travelling by car, so buses are probably subject to the same.
and they seem to be able to cope with normal seasonal variations in weather.
they cope to a degree, but so do trains surely? A few years back now I think, I was on one bus and missed a 'connection' into another in icy conditions. I think the missed 'connection' was down to the bus driver (justifiably, probably) taking it slow. That's one thing that seems the same with buses and trains, in both cases most (but not all) 'connections' will
not be held.