Proposed features/Bus Sluice
|Definition:||a hole in the road too wide for small cars, but navigable by buses|
|Rendered as:||red line across the road?|
In Denmark and the Netherlands (at least) we have a contraption called a bus sluice - a hole in the road too wide for small cars, but navigable by buses and other wide vehicles - for pictures, see:
In the UK, there are these and stuff like rising bollard plugs.
For how it could be done without adding further keys, see 
Bus gate: three ways linked to two nodes (close together). The ways on the outside are highway=cycleway and the one on the inside is highway=unclassified or whatever and access=no psv=yes. To make it clearer I have sometimes used highway=service to distinguish it from the roads at either end. (David Earl on the talk list)
Could be shown as an orthogonal line across the road (in red, perhaps?).
Please use the discussion page for comments.