When you say sideways you mean rotated 90°, so the type ends up vertical?

IIRC Frutiger (and Hans-Jürg Hunziker, who executed the drawings) did some interesting work in this field when designing the «Alphabet Centre Pompidou», which was exactly intended to be set vertically for signage; the optical corrections (like making verticals very slightly thicker than horizontals) would be applied correctly for setting at *90 degrees*, so technically the «wrong» way round if you look at the type horizontally (but it's really very subtle). This is mentioned (though frustratingly briefly) in Frutiger: Typefaces. The Complete Works, pp. 248/249 (for the German edition, not sure if it's on the same pages in the English one).

thanks, i don't like very much the frutiger typeface but I'll try
;-)

?
I wasn't talking about the Frutiger typeface, but about Adrian Frutiger, who drew that but also lots of other stuff.