[OSM-newbies] OpenStreetMap is cool but confusing!

[Richard Fairhurst]

(First of all, glad you find it cool and enjoyable!)

k6web at petesguide.com wrote:

>> I've uploaded a simple GPX tracklog, loaded it into JOSM, converted it
>> into a way, tagged it with the right highway class and street name,
>> and then uploaded the result. I did this Friday, yet still see no
>> results on the published map (either renderer), or even any way to  
>> confirm my edits have been recieved. (not even my GPS tracklog  
>> shows up, even though others in the city do)

Have you expressly uploaded your GPS tracklog? JOSM won't do this for  
you. To upload, use the 'GPS traces' tab on the main site.

Your edits don't show up instantly because the map is only rendered  
once a week. Have a look on the FAQ on the wiki for more.

If you want faster gratification, you can use the other layer, and  
request that your part of the map is rerendered by using the  
informationfreeway.org website. Have a look at the wiki docs, and do  
post again here if you're still stuck.

>> And I found the entire editing process counter-intuitive (and I've
>> been using AutoCAD and other CAD software since 1992!)

I think you should start with the Flash editor (Potlatch), on the edit  
tab of the main site, rather than trying to start with an editor  
(JOSM) designed for power users.

(But I would say that as I wrote Potlatch. ;) )

OSM is purposefully _not_ CAD and CAD isn't OSM.

>> It's basic questions that I have difficulty finding answers to,
>> such as:
>> * Should I record just one tracklog per street, or two (one going
>> in each direction)? I've seen both in this town, and the  
>> double-line ones look bigger and uglier, and both "sides" don't  
>> consistently follow each other.
>> Which is the right way?

Draw one OSM way per carriageway.

>> * When collecting tracklogs, should they be of the middle of the
>> road, the curb edge, or the center median?

Your tracklogs are that accurate? :)

Middle of the road is best. But you should only use tracklogs as a  
guide for positioning your ways, as per...

>> * In converting the tracklogs to ways, it doesn't seem there's
>> actually a way to use the data other than tracing over it, and the  
>> "tracing" provides no means of snapping, thus reducing the accuracy  
>> of the input. Surly there  must be a way to convert a GPS tracklog  
>> directly to a way, or at least snap to it?

Yes and no.

There is a way to do this (and I don't use JOSM enough to be able to  
tell you how, but someone else will be along in a minute to explain).

But IMO you should only use it for long country roads, and only if  
your GPS is smart enough only to record points when necessary (e.g.  
Garmin Geko/eTrex in 'auto' mode) - or you've postprocessed the file.

If you just convert your tracklog as is, the result is a way with far  
too many nodes, and one that follows your swerves and corner-cutting  
rather than the actual route of the road. We aim to have  
better-quality data than that. :)

>> * Perhaps most confusing, at least one page on the wiki talks about
>> using the timestamps from the GPS tracklogs for computing road speeds,

It says it's something we _could_ do, not that JOSM, or anything else,  
is doing it right now. OSM's a big project. :)

>> but if you're just visually tracing the GPX files, how is this data ever
>> used, and how relevant is it if I'm collecting tracks while driving my
>> bicycle on a street meant for cars, for instance?

Statistical analysis would sort that.

cheers
Richard