[Openstreetmap] Re: road names

[Simon Hewison]

Tom Carden wrote:
> Yes, and in the UK at least we have streets which change name half
> way, and other such strangeness, so you definitely want to be able to
> at least override street name data at the line segment level.
> 
> But are address ranges really the same sort of information as street
> name?  Can you show us an example of a map which shows them?  I
> suspect they'd be a separate tag, but I'd be interested to see how
> other maps deal with displaying them.

Pardon the windows avi file, but here's a screen capture video of the
"Route 66" software showing street numbers for somewhere in Tom's part 
of the world.

http://www.zymurgy.org/~simon/route66.avi

I guess I'd better put the usual disclaimer here about not copying the 
data from commercial products. Don't believe street numbers (or names) 
you find on a commercial map, they might be intentionally wrong.

The data they use is from Tele Atlas, and street numbers are sometimes 
wrong, but I think that the video I've recorded shows roughly how Tele 
Atlas store street numbers and streets against line segments in their 
data structures.

..which appears to be something like each line segment can have up to 
four attributes relating to street number ranges and step sizes on each 
edge of the line

eg.

(ascii art - view in monospaced font)

           1    step 2     33 35   step 2   47
          +------------------+----------------+
           2    step 2     34 36   step 2   48

With a sample size of about 50 streets that I have personal experience 
of, the data from Tele Atlas has at least two mistakes:

The street that I live on has the house number sequence wrong.
A street that I went to earlier in the week is down as "Elizabeth Close" 
rather than the correct "Queen Elizabeth Close" (as per council street 
sign, and Royal Mail)

-- 
Simon Hewison