Talk:Santa Clara County, California/San Jose Sidewalk Import

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Sidewalk information on roads

According to the main page, you're creating sidewalks as separate ways here. That's an entirely valid choice, but can I suggest that you also indicate the presence of sidewalks on roads via "sidewalk=separate" as well? It's in fairly wide use ( https://taginfo.openstreetmap.org/tags/sidewalk=separate ) and is especially useful where sidewalks are essentially part of the road (as they are at least in downtown SJ). Further out of town (e.g. Montague / Tasman) it may not less appropriate - there the sidewalks are further away. --SomeoneElse (talk) 20:19, 20 September 2017 (UTC)

I think that is a valid suggestion but I feel like there is a choice between having "sidewalk=separate" vs "sidewalk=left/right/both/none" tags. There are areas in our county with the left/right/both/none tags, and I think it might better to have those tags, though notably redundant, than to have "sidewalk=separate". Especially since certain Tripplanners handle the left/right tags better than sidewalks as separate ways. Thus in this project we'd only add the sidewalks as separate ways and if later somebody else wants to add the left/right tags, they can do that as well. 3vivekb (talk) 23:13, 20 September 2017 (UTC)

You say that you don't plan to add crossings in the original email. If there are no connections between the added sidewalks and the motorable highways pedestrian routing in the city will become a series of islands. If adding sidewalks as explicit ways it is important that pedestrian routing is not compromised during the import. This is one reason to follow SomeoneElse's suggestion. If you don't, I would suggest re-evaluating the order in which you carry out the import. The data remain far more valuable if you ensure that connectivity is complete as each block is imported. Whereas I don't use pedestrian routing in San Jose I have been inconvenienced by sidewalks lacking connectivity in places in the UK. It is important to remember there are people consuming OSM data all the time: furthermore there is no guarantee that they will update the data they use on a predictable interval. If the goal of adding sidewalks is to enhance OSM, it is important not to degrade the data during the process. SK53 (talk) 12:25, 22 September 2017 (UTC)

For this import we don't plan on adding crossings, but immediately after this import we plan to add crossings and ensure the network is complete and connected. We recognize we will be making trouble for routing engines that specifically use sidewalks in the short term. But San Jose is huge and outside of roads is poorly mapped. There is basically no pedestrian routing anyways, practically no left/right tags. Most routers are using the roads. And the workflow for handling sidewalks and crossings is different. Thus, strategically we want to do the two processes separately, adding sidewalks using JOSM and adding crossings using ID. We could do the crossings first, then add the sidewalks, and make sure the sidewalks are connected to the crossings, but I think it would be faster and easier to do it the other way, especially as we will need to add sidewalks that are missing. 3vivekb (talk) 21:37, 22 September 2017 (UTC)
As someone who's mapped plenty of sidewalks and crosswalks in this area by hand, I agree that having the sidewalks in first – even if disconnected from the road network – makes it easier to map crosswalks. Part of the challenge with mapping crosswalks in some neighborhoods is that tree cover makes it more difficult to determine where the crosswalks meet the sidewalks, but if the reasonably accurate sidewalks are present (as they would be with this import), that becomes less of a challenge. I understand the concern about forming pedestrian islands for routers like OSRM and GraphHopper, but it's a high priority for me and others associated with this import to follow up right away with crosswalk mapping – including fixing crosswalks like this that lack connections to the road network. – Minh Nguyễn (talk, contribs) 23:21, 22 September 2017 (UTC)