Icon placement should be scale-dependent

[TransitScreen]

At higher scales (zoomed out) we could consolidate multiple stops of the same type (e.g. bus) into one icon. Google Maps currently does this. [1 and zoom in]

When there are stops of different types (e.g. subway, bus) we could place icons adjacent to each other in a grid. Google Maps does this, and clicking one icon gets you a list of all services. [2]

As the user zooms in, icon placement should reflect their actual physical location.

[1] http://maps.google.com/maps?q=Union+Station+Metro+Station,+Washington,+DC&hl=en&ll=38.898097,-77.004848&spn=0.019956,0.042679&sll=46.948409,7.440233&sspn=0.004376,0.01067

[2] http://maps.google.com/maps?q=Bahnhofplatz,+Bern,+Switzerland&hl=en&ll=46.948409,7.440233&spn=0.004376,0.01067&sll=48.14043,11.56147&sspn=0.136888,0.341434)