On http://sl.se there is a map displaying the public transport network in Stockholm.
The default view looks like this:
showing mostly train and underground stations as well as boat stops.
Zooming in one step results in this:
showing many, but not all, bus stops too. It is not until you zoom in another step all (?) bus stops are displayed.
On the other end, if you zoom out four steps (at least on my screen) you see the whole area SL covers with public transports but now just train stations and boat stops are visible.
A special bonus if I can replace the symbols for trains, boats and so on with a generic symbol that is the same for all types of vehicles. Some dot or ring would be perfect.