Re:
To me old maps show social history, I bought three reprints of the original Ordnance Survey maps from the 19th century based around Hertford, Newbury and Stroud (areas I know well), the most striking thing is how the towns have grown greatly in size and whilst many of the "main" roads remain all have had to acomodate the motor vehicle with dual carriageways and by passes.
In a more modern vein I have 1966 road atlas, again dual carriageways are rare and motorways rarer still, I can only find the M1 and a very short M4.
Yep, I like maps, what better way to spend a winters evening planning a next ride.