Developments in directional road sign design
In the design of signs, in general, and more particularly road signs, international practise has pointed the way…
A reasonable proposition, in improving Ireland’s sign design, is to address the design of the actual type used. It has long been held by type designers that increased x-height is beneficial to typeface designs for signage. Since the 1960s, design for signage typefaces has concentrated on this and other factors of clarity – all notable new designs address x-height. In Ireland, where we’d be replacing the relatively larger uppercase words in English, use of increases x-height would be particularly applicable.
Above: A classic type, Caslon (left), has it’s x-height (height of the lowercase) compared to Transport (centre) and Clearview Hwy, the recent US road sign type. This illustrates the increased x-height of the Transport design, and how this has been surpassed by the Clearview design.
Above: Banks & Miles redesign of Johnston’s Underground Sans circa 1979 – New Johnston (Jury 2002), revised the design to provide increased x-height. This was central to increasing efficiency of London Underground’s directional signs.
Above: An illustration of fitness for purpose in type design. New Johnston Book, which I designed with Banks and Miles in 1990-91, displays ‘exaggerated’ characters designed to maintain the distinctive shapes of the New Johnston typeface, but at reduced sizes and resolutions. It also uses a reduced x-height, to adapt the typeface to use in lengthy paragraphs in ‘book’ type applications. It is because New Johnston was so specifically targeted as a sign and poster type (large x-height) that such a modification was needed for optimal readability in text use.
“If you were to use a large x-height, your signs would be 3 to 4 times the size of what they are” Gerry O’Brien, NRA (Reil 2006)
While this is an understandable observation, in recent years type designs have produced increased x-heights and demonstrated that further improvements in viewing distance can be achieved – without increasing sign size. This would be harder, if not impossible to achieve with uppercase only.The US National Parks service (with responsibility for ’brown’ amenity signs) replaced its Clarendon signs with NPS Rawlinson Roadway, achieving…
“decreased legend length by 10-15% while increasing readability by 11%” (New York Times 2007).
In our context, with Irish language place names often being longer than their English language equivalent, the relative legend length of a chosen typeface would be important.
Another new US type with a significantly increased x-height is Clearview Hwy, this design achieves a distance improvement of 16% over the conventional US Highway type. That is an increase of 80ft at 45mph (Meeker 2004).
Above: Clearview HWY (USA) features an unusually large x-height of 80% of cap-height.
This design runs contrary to the conventional wisdom about optimal x-heights. Jock Kinneir (Kinneir 1980, p68) argues…
“There is a norm , about 76% of the height of the capitals, over which one loses the advantage of the ascenders and decenders, and below which the body of the letters is simply not as effective as it should be.”
I’ll deal with these recent typographic design developments further later, but it’s important to note here that the design of Clearview Hwy was driven by the need to create clearer signs, whilst avoiding the need to create much larger signs, as had been recommended by research (Greene, et al, 1996).