[Talk-us-massachusetts] Help for newbie editing Brookline bicycle accommodations

[Greg Troxel]

Mitch Heineman <mitchheineman at gmail.com> writes:

> I'm working on behalf of the Brookline Bicycle Advisory Committee to edit
> bicycle lanes in town. I've made numerous edits to street features in town
> via iD in the Openstreetmap.org browser, but don't quite understand when or
> how they will show up in the cycling layer. As an example, the map shows
> Beacon Street at St. Paul Street with cycle lanes on both sides of the
> westbound travel lanes, whereas when I query the database, I can see that I
> edited it 10 days ago so that there's a right-hand cycle lane in the
> westbound road segment and a right-hand shared lane in the eastbound
> segment.

Great, and welcome to OSM.

> Any assistance or redirection to someone who can explain the process to me
> would be appreciated. I have many years of experience with ArcGIS and its
> antecedents, but am new to working with OpenStreetMap.

(I am assuming you already get that we have a set of nodes/ways each
with a set of tags, and no concept of layers, even though there's a
messy correspondence semantically.  That seems unrelated to your issue,
but given ArcGIS background I thought I should say it.)

Basically, there is a single master OSM database (or perhaps
replication, but it appears as one).

>From there, one can get copies of the database ("planet files") or a
stream of updates ("minutely diffs").

Each render is (generally) based on a separate database that is loaded
from planet files and/or updated with minutely (or less frequent) diffs.
Often these are postgis, whereas I think the main database is plain
postgresql.

Then, tiles are generated from that database, perhaps proactively (at
small scales), and perhaps on demand (at large scales).

These tiles may then be cached either close to the server or close to
the user.

For the main render on openstreetmap.org, the diffs are rapidly applied
and tiles are invalidated.  Typically after you commit a change, then
within a few minutes you can reload and see it.  Sometimes it takes
"shift reload" to bypass tile caching.  Sometimes the tile server or
various stages are slow and it can take hours or days.

I am really unclear on the update mechanism of the cyclemap.  However, I
would expect these specialty renders to be udpated less frequently, as
that takes computer resources and human time to keep it going.   A new
db load every month would not surprise me.

So you might want to do one or more of:

1)
  a) set up a database with just mass and consume minutely diffs into
  it.
  b) set up a cycle render yourself and make it available perhaps just
  for you, perhaps for town.  perhaps scope it metro boston, but if you
  can make it statewide without pain I bet people would appreciate it

  If you do this, I think MA is basically about 0.1% of the world so
  this should not need a ton of resources; 32G of RAM and 1T of SSD is
  probably plenty (but I haven't done it).  Machines to handle the whole
  world tend to need to be pretty monstrous these days, as opposed to
  things anyone can buy for a $1-2K.

2)
  a) as (1), but look at it with qgis and make some bicycle style (I
  have not tried or heard of it working, but seems like it should be
  doable)

3)
  a) get osmand on a phone (I know this works on android)
  b) use the bike view
  c) enable "osmand live" and select for mass
  d) after committing a changeset, wait an hour and trigger an
  osmandlive update
  e) study the routing.xml (?) stylesheet in osmand (sort of like
  mapnik in concept, but different in details, and spiff it up if
  necessary to show your gradations of shared lanes


Feel free to ask more here, but I suspect 1/2 and 3 are not about MA and
you may get more help by asking other places as well.