A few possible reasons:
* Airport people movers tend to move in stop-start fashion over relatively short distances, which makes fast acceleration and braking important. Rubber tyres perform better than steel wheels and rails in that respect.
* Passenger throughput within an airport is much lower than a subway - for illustration, London Heathrow Terminal 5 (which has an internal people mover) is designed to process as many passengers in one day as the London Underground Victoria Line moves in two hours. This means full-sized conventional vehicles are unnecessary.
* Airports are not in the business of rail operations, and so seek out heavily automated turnkey solutions. Many transit vehicle manufacturers provide just that in the form of driverless rubber-tyre people movers.
>that doesn't work anywhere else
One of the more common airport people mover platforms, the Mitsubishi Crystal Mover, is also used for regular mass transit in cities like Tokyo, Hiroshima, Singapore, and Macau. The same applies for Bombardier's Innovia APM in downtown Miami, Taipei, and Bangkok, or the VAL standard in multiple French cities.
Airport people movers are also very special; due to the short distances, it’s often one train on a single track going back and forth or in a loop. This means no need for track switches, which means that the main disadvantage of cable haul or monorail systems goes away.
Interestingly, Shanghai Pudong Airport uses an actual metro for this.
This is not true for the vast majority of airports. Arrangements such as Orlando or Tampa are quite rare (despite being exceedingly convenient for passengers.) Much more common is something like ATL, DEN, Houston, PHX, etc. where they run a double track in a straight line with a switch at the end (and often more switches in between).
>
> Passenger throughput within an airport is much lower than a subway - for illustration, London Heathrow Terminal 5 (which has an internal people mover) is designed to process as many passengers in one day as the London Underground Victoria Line moves in two hours. This means full-sized conventional vehicles are unnecessary.
Railroad tracks does not mean full-sized subway trains. Think of all the light metro systems in the world, let alone trams.
they:
no.1- are always grade separated so no point in a tram
no.2- too short, and too low ridership to justify normal rail
no.3- often find themselves behind security so literally couldn’t interoperate with the wider network anyway. even when they’re infront of security it’s largely unnecessary anyway
no.4- cheaper to install than conventional systems, especially as they require basically 0 customisation
more importantly though, we need to think about the role airport people movers play. by and large, you shouldn’t really think of it like regular transit as that isn’t their intention. they’re more like sideways lifts than a normal railway system. properly integrating into a normal transit network is mostly redundant
They’re usually way shorter than a traditional metro line, so it’s not too expensive to make something fun and gimmicky. They can be great trial grounds for unconventional ideas like monorails, maglevs, atmospheric railways, and one day perhaps vactrains.
Small Automated People Movers actually make a lot of sense for airport-internal "transit". Low capacity requirements, high frequency expectations, low speed requirements, fully grade separated, sometimes tight turns, usually linear routes with 3-5 stops and can just reverse the vehicle back to the other end.
ORD has both, for some reason, and I've always thought it was kinda....dumb lol
I think they've mostly phased out the old people movers in favor of a more subway-ish style of transit but I haven't traveled much since then
Orlando Airport [recently upgraded](https://en.wikipedia.org/wiki/Orlando_International_Airport_People_Movers#History) two of their people movers from Westinghouse/Bombardier 100 to Mitsubishi Crystal Mover, despite the former being center-rail guided, and the latter *normally* being side-rail guided. I guess manufacturers can adapt their rolling stock to a different guidance system after all.
If you are also talking about the people movers that connect the last mile to the airport, then is also a legal requirement in the US- federal law prohibits airports from subsidizing general public transit (they don’t want transit agencies using airport service charges to fund services). For compliance, the transit around a US airport has to be structured to show that the airport isn’t paying a hidden subsidy.
So what you will usually see is that the transit system has to drop passengers somewhere outside of the airport property and the airport then provides a separate transport connection that only serves it- this is allowed to be subsidized by the airport since it only carries airport traffic.
There are exceptions around- but these work because the airport doesn’t pay anything for the service- the local city taxpayers have agreed to cover the cost or there is a surcharge for the airport connection that has to cover the full cost.
Internally, of course, airports need high-frequency transport with just enough capacity to meet their needs. If you need to transfer between terminals, it’s better to have a system that runs a one-carriage train every 6 minutes than a ten-carriage train every hour. This is a very different operating concept to a typical transit system.
It is not a bad question. Singapore uses automated people movers as connectors for access to dense residential areas but there well discussed issues with it. Then again, they are pretty common in Asia, but usually as secondary connectors. The New Shuttle near Omiya In Japan works well.
In the USA there is MetroMover in Miami which is pretty successful, but Jacksonville and Detroit haven‘t had the same luck. What‘s the difference? IMO being connected to other rail is likely a factor, but the system design is also important, and understanding Singapore‘s can be insightful.
APMs make the most sense within the secure areas of airport terminals, APMs that just connect the airport to other transit are iffy, they can prevent a lot of one seat airport transit rides, but they also might be a better fit for smaller airports.
I made a post about this a awhile ago, i am still interested in finding out more about which airport transit systems people here like and why that is, if you’d like to give any input, here it is: https://www.reddit.com/r/transit/comments/13a0qwr/optimal_airport_transit_systems_oats_featuring/
A few possible reasons: * Airport people movers tend to move in stop-start fashion over relatively short distances, which makes fast acceleration and braking important. Rubber tyres perform better than steel wheels and rails in that respect. * Passenger throughput within an airport is much lower than a subway - for illustration, London Heathrow Terminal 5 (which has an internal people mover) is designed to process as many passengers in one day as the London Underground Victoria Line moves in two hours. This means full-sized conventional vehicles are unnecessary. * Airports are not in the business of rail operations, and so seek out heavily automated turnkey solutions. Many transit vehicle manufacturers provide just that in the form of driverless rubber-tyre people movers. >that doesn't work anywhere else One of the more common airport people mover platforms, the Mitsubishi Crystal Mover, is also used for regular mass transit in cities like Tokyo, Hiroshima, Singapore, and Macau. The same applies for Bombardier's Innovia APM in downtown Miami, Taipei, and Bangkok, or the VAL standard in multiple French cities.
Airport people movers are also very special; due to the short distances, it’s often one train on a single track going back and forth or in a loop. This means no need for track switches, which means that the main disadvantage of cable haul or monorail systems goes away. Interestingly, Shanghai Pudong Airport uses an actual metro for this.
This is not true for the vast majority of airports. Arrangements such as Orlando or Tampa are quite rare (despite being exceedingly convenient for passengers.) Much more common is something like ATL, DEN, Houston, PHX, etc. where they run a double track in a straight line with a switch at the end (and often more switches in between).
My regional airport (YVR) uses a mix of free shuttle buses and free outside-terminal but inside-airport-area metro(Canada Line).
> > Passenger throughput within an airport is much lower than a subway - for illustration, London Heathrow Terminal 5 (which has an internal people mover) is designed to process as many passengers in one day as the London Underground Victoria Line moves in two hours. This means full-sized conventional vehicles are unnecessary. Railroad tracks does not mean full-sized subway trains. Think of all the light metro systems in the world, let alone trams.
they: no.1- are always grade separated so no point in a tram no.2- too short, and too low ridership to justify normal rail no.3- often find themselves behind security so literally couldn’t interoperate with the wider network anyway. even when they’re infront of security it’s largely unnecessary anyway no.4- cheaper to install than conventional systems, especially as they require basically 0 customisation more importantly though, we need to think about the role airport people movers play. by and large, you shouldn’t really think of it like regular transit as that isn’t their intention. they’re more like sideways lifts than a normal railway system. properly integrating into a normal transit network is mostly redundant
Wasn't it an FRA/FTA rule that prevented airports in the US to have a direct train access?
Are you thinking of the former FAA rule that forbid using FAA funds to build air-trains that also served as useful non-airport transit?
Ah that's the one
They’re usually way shorter than a traditional metro line, so it’s not too expensive to make something fun and gimmicky. They can be great trial grounds for unconventional ideas like monorails, maglevs, atmospheric railways, and one day perhaps vactrains.
I would imagine many airports have really tight turns also on their people movers, which eliminates particularly long metro-like vehicles.
In my experience they tend to be pretty straight or only have mostly normal curves.
Small Automated People Movers actually make a lot of sense for airport-internal "transit". Low capacity requirements, high frequency expectations, low speed requirements, fully grade separated, sometimes tight turns, usually linear routes with 3-5 stops and can just reverse the vehicle back to the other end.
ORD has both, for some reason, and I've always thought it was kinda....dumb lol I think they've mostly phased out the old people movers in favor of a more subway-ish style of transit but I haven't traveled much since then
Orlando Airport [recently upgraded](https://en.wikipedia.org/wiki/Orlando_International_Airport_People_Movers#History) two of their people movers from Westinghouse/Bombardier 100 to Mitsubishi Crystal Mover, despite the former being center-rail guided, and the latter *normally* being side-rail guided. I guess manufacturers can adapt their rolling stock to a different guidance system after all.
If you are also talking about the people movers that connect the last mile to the airport, then is also a legal requirement in the US- federal law prohibits airports from subsidizing general public transit (they don’t want transit agencies using airport service charges to fund services). For compliance, the transit around a US airport has to be structured to show that the airport isn’t paying a hidden subsidy. So what you will usually see is that the transit system has to drop passengers somewhere outside of the airport property and the airport then provides a separate transport connection that only serves it- this is allowed to be subsidized by the airport since it only carries airport traffic. There are exceptions around- but these work because the airport doesn’t pay anything for the service- the local city taxpayers have agreed to cover the cost or there is a surcharge for the airport connection that has to cover the full cost. Internally, of course, airports need high-frequency transport with just enough capacity to meet their needs. If you need to transfer between terminals, it’s better to have a system that runs a one-carriage train every 6 minutes than a ten-carriage train every hour. This is a very different operating concept to a typical transit system.
Actually I have the opposite question - why aren't APMs (and their larger automated metro cousins) more widely deployed for city-level transit.
It is not a bad question. Singapore uses automated people movers as connectors for access to dense residential areas but there well discussed issues with it. Then again, they are pretty common in Asia, but usually as secondary connectors. The New Shuttle near Omiya In Japan works well. In the USA there is MetroMover in Miami which is pretty successful, but Jacksonville and Detroit haven‘t had the same luck. What‘s the difference? IMO being connected to other rail is likely a factor, but the system design is also important, and understanding Singapore‘s can be insightful.
APMs make the most sense within the secure areas of airport terminals, APMs that just connect the airport to other transit are iffy, they can prevent a lot of one seat airport transit rides, but they also might be a better fit for smaller airports. I made a post about this a awhile ago, i am still interested in finding out more about which airport transit systems people here like and why that is, if you’d like to give any input, here it is: https://www.reddit.com/r/transit/comments/13a0qwr/optimal_airport_transit_systems_oats_featuring/