A few weeks back, The New York Times Electronic Edition had an in-depth article about the font used in road signs in the USA called "The Road to Clarity" and the accompanying slide show, discussing the evolution over the years. They also cover the traditional Highway Gothic font as well as the Clearview font which has been approved in 2004 by the Federal Highway Administration in the USA.

(image from the New York Times Slideshow related to the article)

On the subject of road signs, EDV Dr. Haller in Germany is developing solutions which enhance CorelDRAW Graphics Suite specifically for the road-signs industry in Germany and in various other countries in Europe. They have solutions to automate the creation of road signs according to the country specific regulations, as well as tools to create the various documents when planning road works. Their solution is recommended by the German Roads Department for all road construction authorities, which means that when you drive on a German highway at 250 km/h (about 150 mph), CorelDRAW could very well have been part of the process of making the signs you see readable.

Gérard