allows both the way(s) crossing the structure and those passing under it to be identified (river and most canals bridges only pass over the waterway, and using only the Way tag bridge=yes means that intersection tests would have to be used to determine the bridges; now we can associate the bridges with the waterway as well.
Bridge type as found in Key:bridge#Values. This should be the "overall type" of the bridge, can be left empty if bridge consists of more sections with conflicting types or if the value would be "yes".
The layer of the bridge. In rare complex cases a single bridge may be partitioned in several sections with different layers in which case this field would be probably best left empty as the individual ways ought to be mapped correctly anyway.
it is a toll bridge/tunnel (but does this make sense for the relation? What if it's a free bridge over a tolled canal?) This is a feature of the footway, the cycleway and the motorway through a tunnel and over a bridge and can be different!
the maximum permissible height for bridges/tunnels with limited clearance (usually derived from a signpost on the bridge) (as per existing tag in Map features) This is a feature of the footway, the cycleway and the motorway through a tunnel and over a bridge and can be different!
maxweight
weight in tonnes
the maximum permissible weight for a vehicle passing over the bridge (usually derived from a signpost on the bridge) (as per existing tag in Map features) This is a feature of the footway, the cycleway and the motorway through a tunnel and over a bridge and can be different!
maxwidth
幅(メートル)
the maximum permissible width for a vehicle passing over the bridge/in the tunnel (usually derived from a signpost on the bridge) (as per existing tag in Map features)This is a feature of the footway, the cycleway and the motorway through a tunnel and over a bridge and can be different!
the ways supported by (on top of) a bridge / passing through a tunnel. Members without a role should be treated as across / through.
under
０
the ways passing under a bridge. This does not in any any way obviate the need to use layer=* correctly and seems useless if not harmful at this point.
outline
必要に応じて１つ
橋やトンネルの輪郭
edge
０以上
outline（輪郭）の代わりとして、側面を表す一対のウェイ。 Rather than drawing an area, a renderer could then draw the parapet marks as now along these ways. 橋の内側がウェイの右側になるように(so if we were modelling a simple bridge using this technique, there would be two ways running in opposite directions parallel to and either side of the road-way which passes across the bridge; but this is generalisable to more complex cases: for example, consider a bridge which has a meeting of three ways on top). もし outline も edge も指定されなければ、レンダリング時には例えば"across"/"through" のウェイが名目上の輪郭として使われるでしょう。
on_bridge
０以上
橋の上にある他の物体。 those should be additionally tagged with location=bridge and layer as described here.
