On 20 Dez., 12:10, Basil Jet wrote:

Since trams tend to have priority at traffic lights on surface routes
anyway, the tunnels exist for the benefit of road traffic rather than
for the benefit of trams, so the car passengers on the tunnel roof are
its real users.

True. I have heard stories from Bochum (I think?) in Germany where one
of the earlier tram subways is now in dire need of a major renoavtion,
but the city doesn't have the money so they are even considering
closing the line as an option. If they would have left it on the
surface back then it wouldn't now be at risk.