[OSM-talk] Some observations from a newcomer

[David Earl]

I've recently joined in doing some mapping. I thought I'd share some
observations. Though I'm new to this project, I do consider myself
technically competent.

To understand the process, I've systematically done the town of
Chapel-en-le-Frith in Derbyshire (pop 6,000), and my home village of
Fulbourn, Cambridgeshire (pop 3,000). I'm planning on filling in the many
gaps in Cambridge city over coming months (what there is so far is mostly
unnamed segments). (If someone more experienced want to review what I've
done, I'd be interested to hear, so I don't propagate things which don't
follow conventions I don't know about).

- Sorry to start with a damning criticism, but the viewer on the home page
is completely useless. It can leave it 20 minutes sometimes and never see
either the landsat images or any data plotted, or sometimes just a small
part. The edit applet is the only way I can look at existing data (from the
web site - obviously, I could use JOSM). I know there are "performance
problems", but frankly the viewer really doesn't work at all. I'm using IE7
usually, but it's the same in Firefox 1.5, and I'm on a 4Mb broadband
connection. I'm wondering whether there is something unusual at my end,
because I can't believe you would have something that is so functionally
useless as the home page.

- It's quite hard to know what's been done already (unless there's nothing
at all!). Some areas look superficially complete, but when you look on the
ground, you find only a skeleton of streets is there. The areas I've done
are complete to the street level (E&OE) but don't include footpaths, and I
know there's lots of foot links between ends of culs-de-sac. It might be
helpful to another contributor to know this. I've put a couple of proposals
on the proposals pages that I would find hepful, but a general way of
defining the level of detail of mapping for an area might be helpful.

- A lot of areas seem to have segments, but virtually no Ways (and no street
names). This seems like wasted effort as if you don't know the street names,
it needs a second survey to pick them up. I found I needed to put the names
I collected into the map soon after surveying (even if I didn't upload it
immediately), or I'd forget the nuances. Main roads form a useful skeleton,
but recording the closes and avenues of a housing estate without adding the
street name data (and hence the Ways) seems pretty pointless to me.

- I tried photographing street name signs, but it was too fiddly turning
camera on and off (and wasn't helpful in the dark), and I decided in the end
sketching a map, tube-style, as I went round was easiest.

- I had to cover some ground twice, just to get to virgin territory, and I
was surprised how much the GPS traces varied. Even when it said 6m accuracy,
I'd find I'd got a parallel track to the previous day more than 6m away, and
it wasn't just being on the other side of the road.

- A question: I've got a railway going over a bridge over a road, but it
shows up going under. How do I force the railway bridge to be an
over-bridge? And can I, with the railway as a single Way, put it over one
road and under the next one it crosses?

- I sometimes wanted to mark the position of a roadside feature (e.g.
Church, filling station). Waypoints are fiddly to enter, and I found the
easiest way in the end was to mark the name on my sketch map, and, as I was
on a bike, just loop around on the road so I got a little circle on my
tracklog.

- Why does osmarender do trunk roads in red and primaries in green? This is
the reverse of the convention usually used in the UK. Maybe other countries
are different.

- I'll post a second message about JOSM.

David