[Imports] Uploading sidewalks in San Jose, California, US

Vivek Bansal 3vivekb at gmail.com
Tue Nov 14 09:23:27 UTC 2017


Thank you for your patience. As requested, we’ve begun to add crosswalks in
San Jose, beginning in the Japantown neighborhood (
We added these crosswalks with the assistance of Crossify, a
work-in-progress tool that streamlines crosswalk mapping, which will help
us finish crosswalks across the city in a reasonable amount of time. We
think the tool has room for improvement, so we’re starting with a
controlled test in a part of the city we know especially well.

Crossify generates candidate crossing ways based on the shape of sidewalks
at street corners – which naturally requires the sidewalks to be in place
first. Rather like the Create Parallel Way command in Potlatch, Crossify is
just a drawing tool to use as a starting point. Before uploading, the
mapper is responsible for deleting each candidate that isn’t visible in
aerial or street-level imagery and manually adding any crossing that isn’t
located at a street corner, and they may still need to move each individual
generated crossing way toward or away from the intersection. Even so, we
think it’ll be easier and less error-prone to whittle down the candidates
than to identify all the crossings from scratch.  After Crossify does a
round, mappers would edit and fill in the blanks using iD editor.

We estimate that some 19,000 crossings will need to be added to connect the
sidewalks we’ve already imported, about 77% of all the sidewalks in the
city. Based on Michael’s estimates, it would take a mapper at his skill
level 45 hours of sustained mapping to manually complete all these
crosswalks. Since everyone working on this project is doing so on nights
and weekends, the project would drag on even longer than it has with our
focus on building Crossify.

Moreover, the tool is designed to be reused, so as we look to add sidewalks
in the rest of the county (most certainly after we complete San Jose) and
other groups look into mapping sidewalks in their own cities, it’ll be
possible to add the crosswalks immediately after adding the sidewalks.

Here is a github issue you can track development of crossify:

My teammates will most likely finish the sidewalks within two weeks (if
it’s okay for us to continue to proceed on this front). From here on out, I
personally will only work on adding crossings and QA of sidewalks.  As a
full methodology for using crossify is developed, we’d update the wiki
asap, and train our other mappers to help get the crossings in.  It’s hard
to estimate how long it would take to get the map to a reasonable place but
i’d guess completion 1.5 months from now.

Thank you for your time!

Vivek Bansal

On Sun, Nov 12, 2017 at 5:33 PM ajt1047 at gmail.com <ajt1047 at gmail.com> wrote:

> Vivek,
> Back in September you asked in
> https://lists.openstreetmap.org/pipermail/imports/2017-September/005160.html
> for "a community review of our project". What people said in reply were
> things that included 'Please confirm that your process will not be limited
> to "uploading" sidewalks but also ensuring they are properly connected'.
> It's been two months now; which is more than enough time to process and
> deal with that request. Unfortunately, we're still seeing brand new
> "sidewalk islands" being added (just in the last few minutes).  Last month
> you said (see below) "The intention of our project is to have a connected
> sidewalk network of high quality achieved in a speedy manner".  Can you
> please explain what progress you have made towards this?  Even changesets
> that say things like "Connected near sidewalks" don't appear to be
> connecting anything:
> https://www.openstreetmap.org/way/540094239#map=16/37.2896/-121.8238
> If you can't show a deliverable plan to achieve connectivity will have to
> ask you to stop importing, at least until you have connected up the data
> that has been imported so far.  If you can't do that then we'll have to
> look again at the data that has already been imported, as currently its
> presence makes pedestrian routing in SJ significantly harder*.
> Best Regards,
> Andy Townsend, on behalf of OSM's Data Working Group.
> * I'm a regular user of pedestrian routing "on the ground" and am very
> familiar with how e.g. a Garmin handheld will cope with both good valid
> connected data and invalid unconnected data.
> On 16/10/2017 05:41, Vivek Bansal wrote:
> Michael,
> Thank you for following our import and checking on our progress.
> Respectfully, I do understand what Frederik was saying and what would
> happen with this import. I understand how important it is to have a fully
> connected network. The intention of our project is to have a connected
> sidewalk network of high quality achieved in a speedy manner.
> The area we are working in has existing problems with routing, with
> sidewalks not connected to roads. Pedestrian routing is also generally poor
> in the suburbs. Through the process of our import and the subsequent adding
> of intersections, the network will soon be better than when we started.
> I'll put more effort in working with Nick and the Open Sidewalks team to
> figure out the fastest way to generate connections. If that is not looking
> like a successful path we will start doing it manually.
> With best regards,
> -Vivek Bansal (3vivekb)
> On Sun, Oct 15, 2017 at 3:50 PM Nick Bolten <nbolten at gmail.com> wrote:
>> Hey Vivek et al, let's keep in touch and get those crossings going. We've
>> got some tools that can help out with getting those sidewalks connected via
>> crossings.
>> On Sun, Oct 15, 2017 at 3:10 PM Michael Reichert <osm-ml at michreichert.de>
>> wrote:
>>> Hi Vivek et.al.,
>>> Am 20.09.2017 um 09:20 schrieb Frederik Ramm:
>>> > On 19.09.2017 21:09, Vivek Bansal wrote:
>>> >> The Wiki:
>>> >>
>>> https://wiki.openstreetmap.org/wiki/Santa_Clara_County,_California/San_Jose_Sidewalk_Import
>>> >
>>> > Let me try to understand this better. The wiki page says
>>> >
>>> > "We recognize we could be creating sidewalk islands since we aren't
>>> > dealing with crossings or connecting the sidewalks to streets but most
>>> > routing software doesn't use sidewalks and typically uses left/right
>>> > tags. Regardless, adding sidewalks will eventually make things better."
>>> >
>>> > At the same time you are talking about the "pedestrian network" and
>>> > "fundamental infrastructure mapping". But it isn't a network if it
>>> isn't
>>> > connected, is it? You must be mapping zebra (and other) crossings too,
>>> > so that actual pedestrian routes can be computed, or else the use of
>>> the
>>> > data you're adding would be limited to walking between places on the
>>> > same block of houses?
>>> >
>>> > Please confirm that your process will not be limited to "uploading"
>>> > sidewalks but also ensuring they are properly connected to what's there
>>> > on OSM already, and thereby (through crossings etc.), also to each
>>> > other. Otherwise what you are doing is nothing better than MS Paint for
>>> > maps - or potentially worse, since a pedestrian routing engine that
>>> > *today*, because of the lack of sidewalks, snaps start and destination
>>> > to the nearest road and leads the pedestrian along that, might choose
>>> to
>>> > snap to a sidewalk instead and be caught on a routing island.
>>> I seems that you did not understand correctly what Frederik wanted to
>>> tell you.
>>> If you upload sidewalks as separate ways, they must be connected with
>>> the existing network in the same changeset which uploads them.
>>> Unfortunately, the data you uploaded already is not connected to the
>>> remaining network at all. Please fix these thousands of routing islands
>>> and dead-ends within the next days or revert your import. Please pause
>>> your import and get more familiar with OSM before you continue.
>>> OpenStreetMap intends to be a routeable data set. Lots of users fetch
>>> data updates for routing every day, every week or every month and rely
>>> on us. If you upload broken data, their routing software will return low
>>> quality results until the next update.
>>> Example of a result which harms the reputation of OSM:
>>> http://www.openstreetmap.org/directions?engine=graphhopper_foot&route=37.31370%2C-121.75710%3B37.31290%2C-121.75690
>>> Best regards
>>> Michael
>>> --
>>> Per E-Mail kommuniziere ich bevorzugt GPG-verschlüsselt. (Mailinglisten
>>> ausgenommen)
>>> I prefer GPG encryption of emails. (does not apply on mailing lists)
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