Hrm. Well, I'm not that thrilled with the idea of cargate, either, I just don't see a good way to explain away cars for all possible futures, and cars are already everywhere here that looks at least "modern", anyway. I figure if most TV shows (that aren't just about singing and dancing) can deal with car scenes, so could Stargate, and Stargate frequently had scenes set on Earth that had cars in the background. They're much harder for the audio people to deal with but the whole industry seems to cope with that problem. Lot's of shows don't use them very frequently (especially soaps and sitcoms), which is really what I'd prefer, but I'd also like to avoid a gate-room centric show, with each human planet now having their own gate-room because it takes place in the future.
Letting many of the planets at least have
cars would save all the walking scenes while avoiding the nagging feeling that all alien cities and villages are within walking distance of their stargate (which probably led to the introduction of the Ancient's gate-ship for SG-A). Providing a background reason why many other planets would happen to have our current model of cars is just a way to avoid designing cheesy looking fake cars, while really saying that humanity from Earth just expanded to encompass other worlds, taking all our neat stuff with us.
A gate-room centric show isn't bad, because it explains why the main characters walk out of a gate and immediately start intereacting with each episode's main characters, but it also implies that future gates weren't located in protected boonies like Cheyenne Mountain, but pretty much on the White House lawn or the steps of the Capitol. That, I think, would create a plausibility problem becaus the gates were also the future world's Ellis Islands and Port of Long Beach, and a world's capitol is the last
place a security minded person would put a gate.
So how would we really use stargates if we were settling other worlds?
After initial exploration teams walked through and set up a camp, we'd send as much equipment and material as we could to start building. The area around the gate would become a mud-slog just from the heavy traffic, so we'd spread gravel and keep expanding. Most of the early structures would be set up around the gate, and we'd quickly start laying out some roads between the tents and storage buildings, just like a military base we throw up in Iraq or Afghanistan.
Years later they'd move the gate somewhere else, because the first location is crude, ad-hoc, and choked. Then an epiphany would hit. The easiest way to settle an entire planet is to use a Goa'uld cargo ship or a large helicopter to keep moving the gate all around the planet, dumping large caravans of people and supplies at each stopping point. Really bright bean counters, city planners, and geographers would quickly optimize the process.
At some point they'd realize that the quickest way to transport large quantities of materials between planets, for long-term continued trade, is to build a system of maglev trains centered on the gate. The gate would sit on a rotating base so it could pivot at the center of converging track systems, which radiate out like spokes on a wheel.
Sometime later they'd realize that the quickest way to ship large quantities of materials between continents on the same planet is to go find more stargates, put one on each continent and toggle which gate is their planet's primary, and then tranship the loads via another planet whose sole purpose is to serve as a turnaround point.
At least that's how it might be done in humanity's core worlds.
So Each planet has a tight dialing schedule where the sender has a train lined up, charging toward the gate with just enough distance to divert to an alternate track if the dialing fails. If the dialing succeeds, a radio link signal verifies that the destination track is clear and the train, a mile or so long, proceeds through at a hundred or so mph. Then the planet either dials someone else or waits to receive an incoming train, according to the preset schedules. Coming to a core world in an unscheduled arrival would really upset things and cause a lot of stress, but most travel to core world's would start with getting on a train in another core world.
The high-speed trains are just a logical extension of current technology, and the Ashen idea to use the gate to transport commodities. The built-up gate transport system might make a good contrast for the show, because going out to handle an SGC problem would involve going from a place so busy that it makes Manhattan look like a slow medieval village, to stepping out onto a grassy plain or deep forest.
Of course every bit of the built-up transport scenes would have to be CGI, and the stargate teams probably wouldn't have much business gating around the core worlds because their expertise is exploration and conflict on remote planets, and that's also the focus of the show itself.
Perhaps such a transport system could feature in a few episodes if it makes for an interesting plot, but otherwise it could just be set up as part of the backstory and not really be mentioned again, just as SG-1 never dwelt on our dependence on semi-trucks, trains, and ocean transports unless there was a storyline to be found, like Ba'als attempted interception of the cargo ship carrying our first Stargate from Egypt to the US during WW-II.
One other advantage of the mag-lev interplanetary train as a story device is that all such trains would be not only standardized, but the exact same trains are shooting between all the planets, getting re-used just like semi-trailers or Boeing airliners. You only need to build one small interior set of a train car and you could use it for the entire series, and it could be the mechanism that carries the stargate team from the President or directors who dispatched them on one planet, to the President or characters they need to deal with on another planet. I'm not sure that would be particularly interesting, though, but it would be the equivalent of our modern show's "airline flight" scene that explains why scene II takes place in a different city or continent from scene I.
Anyway, I think these kinds of ideas at least open up options for changing some of the look and feel of the show so it wouldn't seem like a rerun with a different cast. I'm not suggesting that the show should
go this way, just that it could, and exploring some of the implications if it did.