These are some of the transit features I would like to see. Some have, of course, been mentioned.
Multi-lane roads, avenues & highways
Trams (Streetcars)
Bus lanes
Subway=elevated rail transition needs to be smoother
Fewer traffic lights
Roundabouts
Road, avenue & highway tunnels
Subway=rail transition
More choice of railway, subway & elevated rail stations
More choice of airports
Bus stations
Intermodal stations i.e. bus/subway/tram
Ability to make maps i.e. roads/public transport
Ability to define bus routes
High-speed rail
Bus stops & subway stations built into avenues rather than
taking up a tile, also proper sidewalks
Elevated train stations directly on top of avenues so that
road traffic drives directly underneath
Larger choice of bridges