Unable to answer "How many car lanes does this road have?" – Boulevard Dubouchage (Residential Road) – https://osm.org/way/797535877 via StreetComplete 62.0:

The actual lanes are somewhat different from the map: a one-street from the North, which turns either left or right immediately, without having to cross the subdivision of the Dubouchage Blvd that goes into the tunnel.

Attached photo(s):
https://streetcomplete.app/p/317662.jpg