In tests with a tachistoscope Gill Sans Bold Condensed supposedly performed better than DIN 1451 and so Gill Sans was used as the standard traffic typeface in East Germany.
The Gill Sans family ranges from Light to the exaggerated Ultra Bold—“because every advertisement has to try and shout down its neighbors,” Gill explains in Essay on Typography.
Gill’s lettering is based on classic roman proportions, which give the sans-serif a less mechanical feel than its geometric contemporaries. The typeface was initially recommended for advertising and headline use, but as the public got used to reading sans-serif, Gill Sans turned out to work just as well for body text.
Gill Sans today
Today over two dozen Gill Sans designs are available digitally, with mainstream reach thanks to its inclusion on Mac OS X and Microsoft Office. It can be seen everywhere, used on everything from corporate logos to movie posters—one industry that has actually embraced the unusual Ultra Bold.
Meanwhile, the legendary Johnston Sans typeface became available commercially for the first time in 1997 as P22’s London Underground, licensed by the London Transport Museum. A variant called ITC Johnston was also released 1999.
Quite a few large companys like to use the font, like hevetica it comes in a wide array of weights meaning it can be bold and eye catching, or subtle and stylish.
Helpful sites to use:
I found this website very helpful when looking for examples and uses of Gill Sans.