Many things to discuss:
So far, excellent ideas!
I am overflowing with new ideas, as well:
Let me break them down into sections starting with Infrastructure and Zoning.
1) General
All infrastructure should be placed not only on a 2-dimensional grid as is the case now, but on a 3-dimensional one. This means that, in addition to defining the location of something North, S, E or W, you also define it by elevation. So, as someone has already pointed out, highways can be underground or at ground-level or above ground level. I suggest a 4-level scheme. This would allow you, for instance, to setup your downtown as such: Ground Level are city streets, sub level 1 are power lines, sub level 2 are highways, sub level 3 are subways and sub level 4 are pipes. These are net set in stone, you decide where you want things. For example, a subway can emerge from sub level 3 to sub level 1 and then go 2 levels ABOVE ground.
2) Subway and other Rail
To begin, let's use the destinction of Local Transit and Long-Distance transit instead of Subway and Elevated rail and ground rail etc. As discussed above, a subway could start underground then move to ground level then the elevated. Similarly, as in NY, the main rail lines start out at ground level and then move underground. So, there should be one tool for local-rail and one tool for distance-rail. Also, no two stations are alike. They vary in size depending on demand and number of tracks. Therefore, I think instead of a station object, there should be a platform object. You build one station building, and add platforms and tracks to it. Furthermore, trains don't just randomly choose tracks. We should be able to design lines and routes and name them. Check out
the New York subway map . So how in Sim City? Start with the track tool and pick a level or sublevel. Lay your track and add platforms and stations at major intersections. Then select the Route tool. Click on a track, it becomes red. Want it to switch tracks and head downtown? then select an adjacent track that later heads into the city. Sim city adds a switch to the track and the line now follows that track. Trains will then follow that route, making stops whenever there is a platform connected with that track. Confused? OK, now you can add another line, that crosses UNDER your exsisting line. ALSO, you can make express and local lines, because trains only stop where there are platforms. Setup 4 tracks and the middle two are express, and only have platforms at major stops. Then you should be able to look at a transit map and see all your lines! Just like New York! Ha.. IM me at CMation201 on AIM if you are completely confused. I also think that what rail is elevated above ground level, you should be able to build directly on top of streets.
3) Busses, too, can have routes. Stops shouldn't take up an entire square, though. Instead, you select a part of a road and the bus stop tool will add little shelters on the sidewalks there. Then you can use the "Bus Terminal" building for a larger station. Oh, which reminds me, if a local transit train is underground, the subway station should be like a bus stop and only make a stairway on the sidewalk, rather than an entire square.
4) Highways and Roads
Someone pointed out that highways in either directions can be quasi-independant. So instead of laying highway in both directions at the same time, lay lanes individually. Same with roads. A road can be 1,2,3,4 lanes in either direction then. On ramps should then be nothing more than roads that merge onto Highways. Here: Lay a road (i.e. Main st.) at ground level that crosses under a highway at level +1. This highway is 2 lanes in each direction. Then lay another road that splits off Main st. and rises up to Level +1 and connects to the highway. Then you can add a lane to the highway at that point. Later, do the opposite, making that new lane an "exit only lane". Why? Because highways usually become congested when the go through big cities, but you don't always 4 lanes do you? Again IM me if I'm being unclear, or email me (CMation201@yahoo.de).
5) Power and Plumbing
You should consider laying power underground in cities. Also, what about a difference between Gas and Water pipes? Maybe that's just too rediculous, I dunno. I don't wanna go overboard.
6) Sea and Water
OK I suppose, with the exception of subs and flying boats (why not?) boats just stay at one level. But let us design or own ferry routes just as rail. Also, someone mentioned industry at sea, such as fishing. GREAT idea. Also, what about cruises... And I also liked older versions of sim city where seaports (and airports) were zones instead of objects. That way, you decide how large it is, and each seaport can be a little more unique.
7) Airports
Like I said, zone them. But maybe with the exception of terminals; setup 4 terminals in your zone for instance, and then you have a place to make subway stops or parking lots etc. Again probably too much detail... but just writing my thoughts down... forgive me
OK, so these were my thoughts on infrastructure. More to come on Zoning.
Love,
Clayton