Should pedestrian directions allow following expressway=yes ways?

[jayaddison]

Hello,

Recently I was trying to help with a concern about pedestrian access to a highway reported at: https://www.openstreetmap.org/user/Jennifer%20Pownall/diary/408540

I misunderstood the problem, but noticed something else while investigating.

With the FOSSGIS OSRM (v5.27.1) routing used by the openstreetmap.org website, I found a case where pedestrian directions follows the BC7 (Lougheed Highway) along a section with expressway=yes tagged:

https://www.openstreetmap.org/directions?engine=fossgis_osrm_foot&route=49.244%2C-122.80676%3B49.233257%2C-122.818383#map=15/49.23860/-122.81324

In this example: there doesn't seem to be much pedestrian pathing available in the area as a preferable way to cross the highway. I've created a nearby note to check with local mappers about that.

My question is: should expressway=yes ways be considered valid for pedestrian routing?

By comparison, motorroad=yes is in an avoid list for the foot-routing profile:

osrm-backend/profiles/foot.lua

Lines 78 to 82 in a27573f

	avoid = Set {
	'impassable',
	'proposed',
	'motorroad'
	},

Thanks,
James

[DennisOSRM]

Thanks for flagging this. After consulting with the wiki, express ways shouldn't be accessible to pedestrians.

Will check if we have a test for the pedestrian profile to ensure this.

[DennisOSRM]

Ok, updating my previous assessment. It seems expressway=yes is descriptive on prescriptive. It describes a road's physical characteristics. It does not automatically mean "no pedestrians".

The right fix is upstream in the data. The existing routing logic does the right thing: explicit foot=no or access=no on the way blocks it.

Adding expressway=yes to avoid would be reaching beyond the tag's defined meaning.

[jayaddison]

Thanks @DennisOSRM - I hesitantly agree with that, because legally pedestrian access may be allowed to highways with expressway=yes in some places.

I'll add a note to suggest foot=no on the segments I am concerned about (I don't have local knowledge -- so maybe they could be safely passable by foot even when some traffic is present, but I am uncertain about that).

Would any negative weighting be appropriate for expressway=yes, or is it best to rely on the presence of better pedestrian path/highway alternatives in the route?

(technically that's maybe a separate question.. happy to mark your reply as the answer to this thread)