Okay, one last map.
Map 1 is something I think is possible in the short term, so long as the Rio Grande Plan is followed.
Map 2 is a bit of crazy-town, but I don't think it is unjustified. Like the Rio Grande Plan, it utilizes a special tax district to pay for transit improvements that will in turn underutilized industrial areas into urban neighborhoods. The trunk project, including the stop spacing, is based heavily on the Chicago CTA north shore line, so there is precedent for such a thing working in the real world.
Map 3 returns to my old thoughts on Autonomous Rail Vehicles (from my embarrassing old autonomy blog), which I still predict will fundamentally change how transit systems work.
Imagine a 3-car train reaching a place where the line splits 3 ways. Our human-operated trains with a single human driver can go in only one direction. Three trains will need to go by before every line is served by a train. Not with autonomous trains. Like autonomous cars, each car of a future smart train will be able to operate automatically, without a human driver. When a 3-car train comes to a 3-way way junction, the train will uncouple and each train car will go down a separate route.
Imagine trying to catch a train downtown, but instead of getting on the right colored
train, you get onto the right colored
car, because every train will have at least one car headed to where you want to go.
Though not autonomous yet, the S70 LRT vehicles (the same as UTA TRAX) in Portland have passenger seating in place of an operator cab on one end of most cars. This is how all LRT cars will look when they become autonomous.
Mock-up of a TRAX car without a mechanical coupler. See also the UTA S-Line and the Atlanta Streetcar.
So how will a light rail network operate when individual cars have no human operator, and are not coupled to each other?
The answer is, they will operate in Platoons: groups of train cars, operating like a single train at stations, through intersections with cars, and around sharp curves that restrict speed. When the branch lines begin to, uh, branch out, then the cars will all go their separate ways - but in the downtown area, the cars will need to work together to achieve the maximum capacity.
In Map 1, I proposed 2 downtown loops. In map 2, I proposed a 4-track 'Trunk' between Ballpark and Murray to increase capacity. Now in Map 3, in addition to 3 new branch lines I would like to see, I am proposing that all stations downtown be lengthened to support 6-car operations. There will need to be crosswalks at both ends of the station, and one in the middle too, in order to handle the expected demands - but even with 12' crosswalks at all three locations, this station should be just short enough to fit everywhere that there is currently a station downtown:
Diagram of 6 TRAX cars stopping at a downtown station in 2 groups of 3.
So now, finally, I present you with my ultimate TRAX Fantasy Map:
Including the 2 Circulator routes, I have created a total of 12 routes converging on downtown (as opposed to the current 6). Combining this with a hard limit of 2 minutes between trains downtown, and you get a frequency of a TRAX car arriving every 4 minutes across
ALL Lines. No matter what TRAX station you begin at, there will definitely be a TRAX car headed for downtown within 4 minutes of your arrival.
As for the downtown loops, if there is a 6 car platoon arriving every 2 minutes, that means there will be 180 cars arriving ever hour. Assuming a maximum capacity of
225 people per car, we get a maximum of 40,500 people per hour arriving in downtown
per direction. But because the downtown loops can be approached from either direction, and because we have a 4-track TRUNK line leading directly into downtown, we can assume that 2 trains will be entering the downtown loop from either end of the loop every 2 minutes.
So the final hourly capacity of TRAX into downtown reaches
81,000 people per hour. For reference, the current maximum capacity into downtown (assuming 4 car trains on all 3 lines 4 times an hour) is just over 10,000 passengers per hour. With 10x the current passenger capacity, downtown Salt Lake can become insanely dense, which of course it will, since there will be no parking lots, no parking garages, no on-street parking, or any need for storing unneeded vehicles. Downtown will be for people, and neighborhoods will be reconfigured to prioritize people, not vehicles. Getting into downtown via a car will be a serious pain. It will be much easier (and cheaper), to ditch your car at a TRAX station (it will drive itself away, no need for a park-and-ride!), and hop on the next TRAX car, which will arrive in less minutes than you have fingers on one hand.
Can TRAX handle a majority of traffic arriving into downtown? Well, 1) TRAX will also have the help of BRT on State Street and 2nd South, as well as 2 commuter rail lines - and 2) 80,000 people per hour is approaching NYC subway numbers for capacity (just one line, not network), which is pretty insane for a light rail system. So yeah, I think TRAX, with this configuration, will be able to handle Salt Lake City's transit needs for a very, very long time.
Overall, this project has been mostly therapeutic for me - getting incessant ideas out of my head so that I can focus on other things, like work, family, and the Rio Grande plan. But I don't think it is
entirely a project of self-indulgence. The day of the Robotaxi is coming, and with it the death of all transportation forecasts. My car can already do basically all the freeway driving on its own, so long as I keep a hand on the wheel. Sometime next year it will be able to do ALL driving EVERYWHERE on its own with the same stipulation. It won't be much longer before robotaxis arrive in force - and when they do it will be a Dreadnaught moment for every transportation agency in the world.
The Dreadnaught, if you recall, was a battleship so overpowered that it made every other naval ship in the world obsolete. Navies worldwide began scraping, replacing, or upgrading their entire fleets so that they would not be caught off guard by the new tech. The same thing will happen for transportation planning. Robotaxis will make every long-term transportation forecast, model, and plan totally wrong, because all of these models were constructed around the ability of human drivers to inefficiently use up road capacity.
So what will these transportation planners do? Will they panic and quit? Will they plug their eyes and ears and go on building more capacity that won't be needed? Or will they turn to transit?
And if they do turn to transit, which projects will they work on?
I hope that, just maybe, I can plant a few seeds now before the Dreadnaughts arrive. Hopefully I can one day take a train from downtown to the Cottonwood Transit center, and do so without waiting. But even if that never happens, at least I got these ideas out of my head and onto the internet, so that now I can get my brain back for more important things.
Peace out, guys, and have a happy new year!
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Hopefully the Trib picks it up next!
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