Not directly related but for your information a signage system was exhibited at “Asphalt” and the taxonomy of the data was quite well done and useful.
Discussion of Clearview at typographica.org.
Signage Design Manual by Edo Smitshuijzen.
p.s.
I forgot to mention, scroll down to Legibility.

Phil Baines and Catherine Dixon’s “Signs — Lettering in the environment” might be a good start.

The Design Museum has an article about the work of Jock Kinneir and Margaret Calvert for Britain’s road and motorway signage system.

Also, here is a review of Driving lessons: exploring systems that make traffic safer:

http://www.cmaj.ca/cgi/content/full/168/9/1163

eye 34, winter 1999, major article on Kinneir and Calvert.

Thanks for the great suggestions, everybody, it’s a big help!

There is an interesting article by Ole Lund in Typography papers, vol. 5, 2003
“The public debate on Jock Kinneir’s road sign alphabet”

Not to mention Jock Kinneir´s own “Words & Buildings”, a very lovely book.

In earlier threads Wayfinding: People, Signs and Architecture was recommended by Terry Biddle and Linda Cunningham, who have both studied the subject.

Danish designer Per Møllerup has written a book, Wayshowing, A guide to Environmental Signage (the link goes to a site dedicated to the book). The typography section is a bit thin, though. It could still be of some interest.

James Montalbano of Terminal design and his Clearview is more to the point on the legibility of roadsigns, as can be read on this dedicated site.

I second Wayfinding: People Signs Architecture by Arthur / Passini. (As far as I know, Romedi Passini coined the term “wayfinding”.) Anyway, this book describes very well the kind of problems people have with navigation, and with signage, in a very human way. I could quibble with some of the typographic advice, but it’s still an enormously helpful book. In my experience though, the problem with wayfinding is getting other people (designers / architects) to agree with the more fundamental descriptions of human subjectivity. For literature about that, I would recommend The Design of Everyday Things, by Don Norman. Although not specifically about wayfinding, he writes about user interaction with designed objects in such a way that useful lessons can still be drawn. “Make the right thing easy to do, make the wrong thing difficult or impossible to do, make it easy to fix mistakes, give feedback” — all principles which should apply to good wayfinding. In particular, the distictions he makes about long- and short-term memory, or knowledge in the head / knowledge in the world, are very useful to bear in mind when thinking and talking about how people understand signage and wayfinding.

All these suggestions do not really answer the question as posed. I have a lot of research papers here (that’s what he really needs); some discuss materials, and most discuss the numerous significantly different and noninterchangeable issues James raises (“reading, legibility, readability, and comprehension”). I also know many of the leading researchers and I know where to go to find citations. Contact me directly (joeclark@).

—
Joe Clark
http://joeclark.org/