Flying in Europe, it is about a 50/50 chance as to whether you get on the plane from a jet bridge or you take a bus to the plane parked on the tarmac. In contrast, most US airports have jet bridges, even when the plane is small unless it is a very small airport.
Why?
Jet bridges only work with airplanes above a certain size, such as Boeing 737 and above. Airports that also serve smaller aircraft need to have infrastructure in place to board from the apron, and once that infrastructure is in place it can be used for both big and small aircraft.
Boarding from the apron is a lot more flexible as it’s basically a matter of getting the aircraft onto any available parking spot, and then shuttle passengers to and from the aircraft. So delayed flights are more likely to use one of these spots, as the Jet bridge schedule requires a lot of planning.
While the above probably isn’t a root cause, it’s definitely a factor.
Source: Frequent flyer, on both big and small aircraft.
Nah, I worked at an airport that only has CRJs and we had a jet bridge. I’ve even boarded Saab 340s from them. There are some differences like a little bridge instead of direct connection, and they can’t use the jet bridge’s auto-level feature (as the plane gets loaded and unloaded it slowly sinks/rises not unlike what a car would do; auto-level has a stick with a wheel to track that and move the jet bridge to match) but other than that it’s pretty seamless.
Ok, there is a limit and you probably couldn’t use a jet bridge on, say, a Cessna Caravan… But the minimum is most definitely not a mainline plane.
I’ve taken jet bridges to board Embraer 175’s in the USA. In contrast, I’ve gone up stairs for an Airbus A321 in Europe.