Yes, most of them seem to be Frutiger, though many of the German signs are in Univers/ Helvetica nd one in Portland is Futura. In signage, sans-serif rules!

Hi Omar, thanks for linking to my article.

Most typefaces used for airport signage is indeed Frutiger, first designed for Charles de Gaulle, Paris. Other typefaces that can be used for airport signage are eg. FF Info (Spiekermann), FF DIN (Albert Jan Pool), FF Transit (MetaDesign). I have seen uses of Helvetica and Gill Sans, although I find those typefaces not very suitable for airport signage. Good luck.

If I remember correctly, just like Frutiger, FF Info was designed especially for airport signage (Düsseldorf airport).

One I like, especially the little figures, from Katowice airport in Poland.

Seattle is Myriad, and it's too bold, like most signage type, especially when reversed out of dark.
Katowice is FF Info. And i like the regular weight better than the bold above.