Great design is defined not by how nice something looks, but by how well it works. My favourite things, those contraptions where the design is beautiful, have an intrinsic elegance based on how they perform when used. The elegance of the single speed, fixed wheel bicycles I restore – the bare minimum required to make the most efficient human powered transport. The simplicity of the Converse Chuck Taylor shoes I’ve been wearing each day for 15 years – long lasting, renewable rubber and canvas, built with a minimum of fuss.
Recently I came across a story by Ralf Herrmann about designing a typeface for street signs.
The story begins in 2006 with a trip down Route 66. Day in, day out, I looked at U.S. traffic signs that were either set in the old, somewhat clumsy “FHWA font series” or the new Clearview HWY typeface. Approaching the signs, I would often test myself: which typeface works best from a distance, and which of its features or details might be responsible for its performance.
Herrmann started with the human-based outcome of the most legible typeface possible. It’s a great illustration of applying rigour to the design process and three things stood out while reading.
Distinguished Letter Forms
First, was the application of visual principles to the form of the letters – a very practical application of the “design eye” ideas I’ve been talking about for a while. Helvetica is a great font. Simple in its design, stripped of all clutter with a grid-based form that’s symmetrical to a fault. When introduced in 1957, Helvetica was a demonstration of elegance that designers of the time (and since) embraced enthusiastically. Its now such a universal presence it has its own movie and a wave of detractors keen to show their design independence.
Helvetica is not the only font used for signage, but its perfect grid-based geometry make it a good baseline for highlighting the distinguishing marks used to improve legibility. Herrmann’s font is not based on Helvetica, its built from the ground up, but contrasting letter forms between the two typefaces highlights how Herrmann came up with the shapes for his perfectly legible type.
Here you see how the grid-base of Helvetica, clean and regular as it is, actually inhibits the ability to quickly discern between different letters like ‘R’ and ‘B’. Helvetica is naked of serifs. Serifs add a degree of visual clutter, but aid in reading quickly. The elegance in Herrmann’s work is in modifying the letter forms for every character just enough to make them distinguishable at a glance while still keeping an overall visual harmony to words when the letters are combined on a sign.
Second was the use of visual tools to refine and test the character forms. For as long as I can remember, I’ve used a little trick to assess designs where I shrink the screen down to about 1/4 size and see how the visual hierarchy looks when details are obscured by being too small to digest. It’s a crude attempt to get a sense of the pre-attentive view of a screen. Herrmann went to the effort to build a Legibility Test Tool. Awesome!
For street signs, different weather, lighting and distances are key to legibility. Simulating these conditions, like the “glow” of a reflective sign above, provides a test tool to help refine each letter. Before you give up on this great idea as being not worth effort to try, you might not need such a sophisticated approach for what you’re building; eg, if your building a web app, try hitting ⌘- (Command-Minus) a few times in your browser. How well can you access your core functionality this way?
The Form of Function
Since Donald Normal raised the awareness of affordances in design, there’s been an expectation that in great products, form and function are inexorably linked.
Comparing each of Hermann’s characters one-on-one against a grid will identify tails sticking out, a mixture of angles and even different line widths for light-on-dark vs dark-on-light contrasts. The driving function of legibility forces each character to be sufficiently different to read in a glance. Homogenous forms may be visually more balanced, but fail to excel at the core task of being understood at a glance while hurtling down the road.
Individual letters are not where a sign typeface needs to excel. The subtle elegance of Wayfinding Sans Pro is in the clarity of phrases rendered next to each other on a sign. The detail in each character is there, but hidden in how effective and legible words are when rendered. It’s a great example of a carefully crafted contraption that gets its beauty from its high performance.