Was just wondering how they measure the distance.
I.E. M4 Reading 16 miles is this to the centre or the start of the boundary.
It used to be the distance to the main post office in a town, no idea if it still is.
It used to be to the Town Hall, but I’m not sure if it still is or not.
Two very interesting replies. 
tallyman:
It used to be the distance to the main post office in a town, no idea if it still is.
Yes it still is if the town in question still has a main post office,this question was asked on Radio 2 a few weeks ago,i’m not sure if i remember rightly here,but if there is no main post office,it’s measured to the Town Hall ? 
I think it depends who is doing the measuring as to the point they pick a local sign to me says ‘x town 4 miles’ last time I clocked it in my car it was 7.5 miles!!!
Norfolknewbie:
I think it depends who is doing the measuring as to the point they pick a local sign to me says ‘x town 4 miles’ last time I clocked it in my car it was 7.5 miles!!!
A car mileometer is always slightly inaccurate,but i suspect the measuring stick used to pinpoint the distance to “x” town was even more inaccurate! 
The distance is usually measure from/to the town centre or post office.
It’s often said that London distances are measured from Charing Cross station, but they are in fact are distances to a statue of King Charles I just south of Trafalgar Square, which marks the spot where King Edward I was buried in 1290.
Cambridge is an odd one, as you come along the A428 towards Madingley the signs show a very short distance to Cambridge. Just past the American cemetery you come to a Cambridge sign before the M11, the distances relate to that point, but you can see where they have changed the signs by fixing a sticker or plate over the old distance.
Harry Monk:
It’s often said that London distances are measured from Charing Cross station, but they are in fact are distances to a statue of King Charles I just south of Trafalgar Square, which marks the spot where King Edward I was buried in 1290.
Edward i died in 1307. His queen, Eleanor of Castille died in 1290. The various “Cross’” around London were built as a tribute to her by Edward. His successor (Edward ii ) was deposed and murdered with a red hot poker shoved up his bum. 
Edward i was the English king portrayed in Braveheart, despite what Mel Gibson thinks Edward was one of the greatest English monarchs.
i alway thought it was the man post office as well…
here’s a good one, revesby lincolnshire on the b1183 where it meets’ the a155…
horncastle 7 mile’s
now turn left, up te road not even 1/4 mile, your now closer to horncastle by a mile…