[OSM-talk] Map Co-ordinates for towns, etc in UK
bareman at tpg.com.au
Sat Mar 3 04:10:46 GMT 2012
On Fri, 02 Mar 2012 21:14:47 -0600
"John F. Eldredge" <john at jfeldredge.com> wrote:
> mick <bareman at tpg.com.au> wrote:
> > On Fri, 02 Mar 2012 20:16:18 +0000
> > Philip Barnes <phil at trigpoint.me.uk> wrote:
> > > I have found some interesting stuff whilst playing with routing on
> > > http://open.mapquest.org (which uses OSM). Have found that it cannot
> > > route to Shrewsbury.
> > >
> > > Have found that the town waypoint has been put in the middle of a
> > retail
> > > area, with pedestrianised streets around. Am guessing it is because
> > it
> > > is too far from a road. It works if I ask for High Street,
> > Shrewsbury.
> > >
> > > Have moved it so that it is close to High Street and once mapquest
> > has
> > > updated the map I will see if it works again. But maybe this is
> > > something else we should consider.
> > >
> > > A good example of TomTom/google getting it wrong is Ironbridge,
> > where it
> > > leads you into a back street, rather than the centre i.e. the
> > bridge.
> > >
> > My Navman (MY50 I think) also has problems generating a route to just
> > a town or suburb without a street name.
> > At the times these towns developed very few people had a car and even
> > fewer had sat-nav units so the 'rule of thumb' didn't need to take
> > vehicular access into account. Now social engineers have had their
> > evil way, the 'rule' joins dinosaurs, woolly mammoths and this old
> > System/370 operator on the dusty shelves of the museum and its up to
> > the new generations to clean up our mess.
> > mick
> Another issue you are likely to encounter is a town that has grown in an asymmetric manner, so that the current geometric center is offset, perhaps by a large amount, from the historic center point. This is particularly true where a natural barrier, such as a lake, adjoins the town.
> Here in the USA, some small towns that have experienced most of their growth during the automobile age are essentially one-dimensional, extending for several miles along a main road, but extending only a block or two at right angles to that main road.
My original interest was if there was a specific point that said 'this is Sometown', where distances to adjacent towns were measured from, similar to the Australian convention where the "Zero Point" was set at the roadside, at the Post Office which was usually next door to or across the road from a 'coaching inn'.
This point rarely had anything to do with the geographic centre of town but served only as a survey benchmark.
As Phillip, yourself and a few other people have pointed out these points have little remaining relevance in current times, especially for routing.
The only place where I've found this concept still in use is Queensland Rail's Brisbane suburban network, where the track at stations is marked with the distance to Central Station and the markings are maintained.
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