Airport west, Jilong East.
As well as the obvious empirical evidence there’s also the logical fact fo the roads. Taipei has a grid of north-south and east-west roads. Following these roads from Taipei Main Station, you need to head East to get to Jilong and West to get tot he airport.
(Although it suddenly occurs to me why many Taiwanese will say north and south. If you are taking the freeways (1 or 3) you need to go ‘north’ for Jilong and ‘south’ for the airport).
Brian
I told some locals I was going to the south. They asked me where, and I said “Taidong”. They said “Taidong’s EAST, not south!”
Never mind that Taidong is west of Taipei and south of Tainan.
… and Taiwan is east of China … not south … 
Taiwan is south of Beijing …
Is the problem that people here are taught to think in different terms about where ‘here’ is and what N,S etc are in reference to?
It’s hard getting people to understand the difference between ‘in the north of’ and ‘north of’ in English, even when their language skills are up to it. Do these concepts apply in Chinese?
When I used to live in Pingdong, I noticed that every Taiwanese person I ever met would insist that Pingdong is south of Gaoxiong, when in reality, it is almost directly east of Gaoxiong. (And actually the center of Pingdong is slightly north of the center of Gaoxiong).
Taiwanese people would always say things to me like “The weather in Pingdong is definitely hotter than Gaoxiong because Pingdong is south of Gaoxiong.” Then I would correct them and say “No, actually, Pingdong is east of Gaoxiong! And actually, the temperature in Gaoxiong is usually about the same as the temperature in Pingdong.” And then they would just stare at me with a shocked expression, with their mouth open.
I think part of the problem is they are all forced to take classes in “Geography of China” in secondary school, but they never take any classes in “Geography of Taiwan”.
Here’s what Wikipedia says about “north.”
[quote]North can mean:
true north, the direction along the earth’s surface toward one pole of the earth’s rotation, namely the pole that is clearly on one’s left when standing at the Equator while facing the rising sun.
magnetic north, the direction along the earth’s surface in which horizontal magnetic field strength has its most positive value (but see Flipping of planetary magnetic poles for an eventual event, so rare as to make unlikely any advance agreement on whether one or two retronyms would be involved in the replacement terminology)
a loosely specified direction, usually within half a right angle of true north, especially when stating travel instructions in an area where directions of travel are constrained by an approximately rectangular grid of streets, hallways, etc.; this is often called ‘grid north’ or ‘plan north’.
the orientation of a traveller with respect to a visible or otherwise definite continuous two-way route, such that sustained travel over the whole of the route produces a change of position to a location further north, even if that involves travelling a part of the route in another direction, even straight south; often termed “northbound”.
pertaining to the part of a route mainly or exclusively used by northbound traffic, where southbound traffic is separated by barriers, or where both are encouraged to stay mostly in one portion by Rules of the road; often termed “northbound”. [/quote]
So there you have it. The people have spoken!
[quote]4. the orientation of a traveller with respect to a visible or otherwise definite continuous two-way route, such that sustained travel over the whole of the route produces a change of position to a location further north, even if that involves travelling a part of the route in another direction, even straight south; often termed “northbound”.
So from these two definitions, and the directions of the freeways, you could actually be justified in saying Jilong is north and the airport is south. 
Never mind. Stupid post. 