Suggestion: show sidewalks (in the same brown as footways)

[DerDings]

While not originally dedicated to cyclists, sidewalks can be important to them, too. A street which has a sidewalk can easily be stopped along nearly everywhere. Cyclists can rest safely, apart from the carriageway.

In some cases cyclists are even allowed to use the sidewalk directly

• wheeling their bikes in places where they feel unsafe on the road, e.g. at large crossroads without cycleways
• if they are children (e.g. in Germany children up to 9 years may cycle on the sidewalk)
• if they're an adult accompanying a child which is supposed to cycle on the sidewalk

From the perspective of a user not familiar with osm mapping practices, it is not clear why some sidewalks (the separately mapped ones) are shown while others are not.
So i suggest rendering sidewalk~right|left|both the same way cyclable sidewalks are already shown, but in a different colour. Footway brown should fit.

Naturally regular cycleable sidewalks should remain green as it was explained in #409 and implemented in #464.

[stellingsimon]

Please also consider the following:

1. There are a lot of sidewalks. By coloring all sidewalks, we'll add a lot of lines to the map. This may hide actual cycleways, which I consider a negative side effect of the proposed change.
2. The presence of sidewalks does not equal "safety". For example, where I live, many roads without sidewalks have speed and access restrictions that make them much safer than a secondary highway with sidewalks.
3. Sidewalks that are mapped separately are often well-separated or at least very broad compared to normal sidewalks, which make them extra safe and more comfortable to use with a bike. As a map user, I actually benefit from "highlighting" separate sidewalks over normal ones. This feature would be lost with the proposed change.

For the above reasons, I propose to not render all sidewalks. However, it may be benefitial to render sidewalks under the following conditions:

• Sidewalks on highway types known to be associated with either heavy traffic or high maxspeeds:
  • highway=[trunk,primary,secondary,tertiary,rural]
• Sidewalks on highways with a maxspeed >= 50 km/h

[DerDings]

1. There are **a lot** of sidewalks. By coloring all sidewalks, we'll add a lot of lines to the map. This may hide actual cycleways, which I consider a negative side effect of the proposed change.

I think those sidewalks should be rendered at a very low rank, even lower than the green bicycle=yes sidewalks. In #464 the ranking is desribed as

A cycletrack (cycleway=track) or a segregated sidewalk, that allows bicycles (sidewalk:bicycle!=no sidewalk:segregated=yes): solid dark blue
A sidewalk designated for bicycles (sidewalk:bicycle=designated): solid lighter blue
A bike lane (cycleway=lane): dashed dark blue
A sidewalk allowing bicycles (sidewalk:bicycle=yes): solid green
A shared busway or lane: very dashed dark blue

Regular sidewalks should be placed at the end of this list.
Cycleways and other paths are already rendered above roads, so a sidewalk wouldn't hide a cycleway.
To avoid having too many lines on the map, rendering sidewalks could start at z15 or z16 and above. These are the zoom levels when also separately mapped sidewalks are starting to stand out.
For making sidewalks not stand out too much, i'd suggest giving them a width equal to footways.

2. The presence of sidewalks does not equal "safety". For example, where I live, many roads without sidewalks have speed and access restrictions that make them much safer than a secondary highway with sidewalks.

I agree with that. But highway classification and low maxspeeds are already shown in the map, which won't be affected by rendering sidewalks.

3. Sidewalks that are mapped separately are often well-separated or at least very broad compared to normal sidewalks, which make them extra safe and more comfortable to use with a bike. As a map user, I actually benefit from "highlighting" separate sidewalks over normal ones. This feature would be lost with the proposed change.

On higher zoom levels, around z17 and above, the gap between a separated sidewalk and the carriageway becomes visible, so one would still be able to distinguish them from attached sidewalks.

For the above reasons, I propose to not render all sidewalks. However, it may be benefitial to render sidewalks under the following conditions:

* Sidewalks on highway types known to be associated with either heavy traffic or high maxspeeds:
  
  * `highway=[trunk,primary,secondary,tertiary,rural]`

* Sidewalks on highways with a `maxspeed >= 50 km/h`

Maybe these filters make sense on mid zoom levels (z15 - z16). If applied on the more detailed zooms, users (and mappers) would again be confused why some sidewalks are shown while others aren't.

[Phyks]

Could we try to gather some examples here where current CyclOSM style is missing useful information and sidewalks rendering would really help? Thanks!

[DerDings]

This place:
https://www.openstreetmap.org/#map=19/51.47209/7.25881&layers=Y
© OpenStreetMap-Mitwirkende

© RVR, 2020, dl-de/by-2-0

Cycling the carriageway of the East-West road is for tough cyclists here. But for children of 9 years or younger, it is pretty safe, because they may use the sidewalks. Also an adult accompanying a child of 7 years or younger may use this sidewalks. (by german law - but it makes sense, so there are probably similar rules elsewhere. EDIT: another example is New South Wales, Australia, where using the sidewalk is allowed for children of up to 15 years)
Even adults may cross this bridge rather using the sidewalk (dismounted) than cycling the carriageway, if they don't feel secure on roads like this.

Also in this place the information about sidewalks is important, but in a completely different way:
https://www.openstreetmap.org/#map=20/51.47317/7.28673&layers=Y
© OpenStreetMap-Mitwirkende

© RVR, 2020, dl-de/by-2-0

The road in the center of the image is a bicycle road. It has a sidewalk, so cyclists and pedestrians are separated. Pretty similar to highway=path segregated=yes, where the footpath is already rendered along (and may become brown some time #450).
The part leaving the picture's frame to the northwest doesn't have a sidewalk, so cyclists need to share the road with pedestrians.

At last, places like this:
https://www.openstreetmap.org/#map=20/51.39274/7.39325&layers=Y
© OpenStreetMap-Mitwirkende

© RVR, 2020, dl-de/by-2-0

This is the last part of a steep road, as can be seen from the contours. Cyclists without motors may want to know if there is a sidewalk so they can fall back on slowly pushing up their bike aside from the carriageway.

So use cases of sidewalks boil down to one of those three cases:

• on larger roads, people, especially kids, may use the sidewalk with their bike in some way
• on minor roads, no sidewalks mean pedestrians getting in the way of cyclists.
• on steep roads, so you can leave the carriageway if you find that you cannot make the whole way up on your bike.

The first two cases cover nearly every road, so I'd be consistent and show sidewalks on every road, without discriminating by category.

[DerDings]

With an SVG of this place https://www.openstreetmap.org/#map=18/51.47195/7.26015&layers=Y, I could try to make a mock-up as a basis for further discussion.

[brainwad]

I actually implemented this, but decided not to proceed to a pull request, because when I tried it, at least in my area, there is much duplication of sidewalks, being tagged both as sidewalk= tags on the main way and also as separate highway=footway ways. The resulting render looks quite ugly and it's not at all trivial to figure out when not to draw the sidewalk= tags.

[DerDings]

I actually implemented this, but decided not to proceed to a pull request, because when I tried it, at least in my area, there is much duplication of sidewalks, being tagged both as sidewalk= tags on the main way and also as separate highway=footway ways. The resulting render looks quite ugly and it's not at all trivial to figure out when not to draw the sidewalk= tags.

As far as I know, there is currently no render showing sidewalks. Due to the lack of visual feedback, incorrect tagging is to be expected in some places.
I would take this as a chance to encourage mappers cleaning up such duplicates as the soon as the first renderer is showing them.

[DerDings]

I just found out that there are regions where cycling in the sidewalk is allowed generally, e.g. Queensland, Australia. Showing sidewalks is even more important there.