Domestic and internationals using same gate
 

If domestic and international flights share a gate, how do they make sure the international arrivals go straight to immigration instead of into the terminal?

The ones I have seen had two exit hallways from the gate. For domestic, they opened the door to the terminal and for international, they kept that closed and directed exiting pax to another hall that led to international arrivals.

interesting. I haven't flown ingternational in decades.

in AMS, the D gates are both shengen and non shengen, with two floors to access the airplanes: one behind customs, one not. When you get off the plane, they just direct you to one floor or the other.

In MSP there is a hallway between the jetway exit and the main terminal that can be closed off and passengers can walk to customs. When a domestic flight arrives the doors to the main terminal are open.

OP has not told us which nation or which airport he is asking about.

In the US, there are many international arrivals where passengers have pre-cleared CBP at their origin and the arrival is logistically domestic. At others, it is simply an intervening hallway with doors which can be locked off or not depending on whether passengers need to be routed to CBP or into the terminal.

When I see this I usually see that they actually have a segregated exit hallway between the gate doors and the jetway..so deplaning intl' pax are contained in the secured area.

Yeah, many airports around the world have it so that deplaning international passengers deplane on to the jetway bridge that leads ascending to the international arrivals level of a terminal while the door and jetway entrance on the departures level side remains closed. That's just one example of how its done. There are various permutations. Then, there are some airports that don't allow this sort of thing at all with completely different terminals/sterile areas segregating domestic and international passengers. Then there are some airports with terminals that share the same building domestically and internationally, but separated by sterile zones.

At PVG, domestic gates are on level 1, and international gates are on level 2; they have different gate numbers, but are actually the same gates (with upward and downward sloping jetbridges). Additionally, arriving international passengers get to use a 3rd hallway out of the jetbridge).

[QUOTE=Often1;29786312]OP has not told us which nation or which airport he is asking about.

USA, DTW and O'Hare.

TLV also used to have buses going from the aircraft to the international arrivals building way back in the day. I haven't been back since they redid the terminal though.

At DTW, you deplane through the jetway into a hallway that is used by both domestic and international; however, for domestic, you're routed one way into the terminal. For international, you'll take an escalator down to the first level then proceed to customs and immigration that way while the main terminal is above you. If you're connecting to a domestic flight, you'll proceed through security again after customs/immigration. If not, then you proceed out toward baggage claim.

Yep, and many airports still use this method, especially the larger Schengen airports.

In HKG, all arrivals go onto the lower level via the jetway’s down slope and departures come from the upper level via the upslope.

At US Airports, the jetways have an alternate exit that goes directly to immigration.

And you have cases where flyers skipped customs, because the wrong route was open(or plane got routed to wrong terminal which was domestic only)

​​​​​​Example:
https://abcnews.go.com/US/passengers...ry?id=35373089

If it does happen to you, raise a fuss... Otherwise, if you leave airport, you'll need to return and be processed via customs