Underground parkings

I tried to draw underground parkings, and I have 2 questions about the best way to draw pedestrian access.

I did the following:
For the entance and exit of cars:

  • highway=service
  • oneway=yes (when relevant)
  • foot=no

For the parking place itself:

  • area=yes
  • highway=service (I wanted to create a road from entrance to exit, but it does not show on the map. I may have to draw this separately from the Area)
  • tunnel=yes
  • layer=-1
  • name=*
  • fee=yes

For the pedestrian access:

  • highway=steps
  • foot=yes

But the Pedestrian access does not show on the map. I think it is a valuable piece of information, so I hoped to see some steps on the map, but there is noting…
The undergrond road does not appear either, but I expected it to be useful for driving assistance software.

Has anyone found a solution?
Could it be a good idea to specify the way to enter these parking data once for all, as I think some have different habits (using fee OR toll, using the service road or not around the Area, …)

I usually add ramp=yes/no to ways tagged with highway=steps, so are you tagging a way or a node as highway steps?

I’m tagging a way as “highway=steps”. A very short way, in fact (something like 1 or 2 meters), and I just wondered if it was not too short to be visible on the map.