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While road signs in general are scientifically researched for many decades in western countries, little is known about the parameters that lead to a maximum legibility of typefaces used in signage. And therefore the range of typefaces used on road signs is pretty wide. We see geometric typefaces…

Road Sign Poland

…slanted serif typefaces…

Road Sign Luxembourg

…and many old and modern sans-serif typefaces…

Netherlands (ANWB-Uu by Gerard Unger)

But which ones are most legible? Early road sign typefaces in the beginning of the 20st century were often designed by engineers with a strict geometric or grid-based approach. Newer designs, such as the new typeface in the Netherlands (see image above), are more based on the tradition of print typefaces. But in my opinion, both approaches have their drawbacks, because typefaces used for road signs have very unique requirements. Many people I have talked to seem to believe that speed might be the most important factor for the design of such typefaces, but that is actually not the case. The speed of motorists only influences the duration in which you can read the text on the signs. But that can simply be compensated by the size of the signs. What makes road signs so different from books and magazines is the variable reading distance. So if you want to improve the legibility of a typeface used for signage, the most important task would be to increase the viewing distance. If you are about to pass a huge motorway sign that is 50 meters away, legibility is no problem at all—the letters are so large, they could be set in Comic Sans and could still be read without any trouble. Where you can make a different thru type design is the moment when the motorist is at a distance where the text is just about to become readable.

A new approach

After traveling all over Europe for three years to experience and document as much road signage systems as possible, I started to design my own wayfinding typeface. This was part of my diploma at the Bauhaus University in Weimar, Germany. After all my practical and theoretical research it became clear to me that the regular way of designing a typeface on paper or on screen was not really appropriate. Because designing a typeface for a large viewing distance is not only a question of type design, it is also question of the feasibility of testing. To increase the viewing distance of my design I needed to experience my typeface in this blurry state where it is just about to become readable and I needed to test it when the visibility is decreased, for example by an overglow effect thru the headlights of a car.

That’s where I came up with the idea of my Legibility Tool Tool. It’s an OSX application that allows real-time simulation of different viewing conditions during the design stage. While I was working on the design of individual letters in FontLab, the tool showed me a simulated view of test words with the letters I was just working on. With this tool I could remove the guesswork and was able to optimize my design even for the worst reading conditions.

(Movie doesn’t work? Check it out at Vimeo…)

Often the simulations were quite surprising. Sometimes I was tempted to design my typeface in a way I was used to from the print world, but the tool clearly showed me that the reading conditions of road signs require a unique design for maximum legibility within this context.

About the design

My wayfinding/signage typeface

So how does the ultimate signage typeface has to look like? When I evaluated existing signage typefaces with my Legibility Test Tool it became pretty obvious that all those stylistic details that define the overall look of these typeface disappear under difficult reading conditions. What matters most is the skeleton of the letters. On one hand these letter skeletons should be very generic, so they easily match the visual patterns we have learned and seen so many times in our life. But on the other hand, they also need to be somewhat unique. The most generic letter forms do not necessarily create the most legible letters, because too generic letter shapes are harder to differentiate. So in my design I used average proportions as a starting point but I also tried to stress the individual character of each letter.

The “a” is a good example of this approach. The prominent stroke ending on the right may not be necessary to recognize it, but if it is there it helps to distinguish the “a” from other characters. Below is another example: Under difficult reading conditions, details such as the usually rather small crossbars of “f” and “t” get easily lost. Making these parts more prominent can significantly improve the legibility under difficult viewing conditions.

Top: German road sign font DIN 1451, Bottom: My wayfinding typeface

Certain letters can easily be mixed up under difficult viewing conditions. Designing those letters in a way where they are easily distinguishable makes the typeface more legible and increases the maximum viewing distance. Here are some examples…

The missing horizontal crossbar of the Dutch road signage font (orange) makes C and G harder to distinguish. In blue are C and G in my typeface. The difference between the letters is easily recognizeable.

Poor differentiation of O and Q in the French road signage typeface (orange). On the right are O and Q in my typeface.

Helvetica (orange) has many letters that are designed very similar, which is not really helpful when used for signage. A more unique design helps to differenciate the letters.

Another typical example: capital I, lowercase l and the figure 1 should better be designed in a rather unique way.

The stroke width is another important factor of a typeface used for signage. “The bigger the better” does’t work in this context—quite the opposite is true. Modern retroreflective sheeting of road signs create an overglow effect which affects the legibility. But this problem is not limited to road signs. Backlit signs in airports, hospitals and office buildings also suffer from this problem. The typeface design should compensate for this overglow effect. This can be achieved by using a thinner stroke width and by opening up the counters of the letters.

Top: Road signage typeface in Spain and Italy; Middle: Transport Bold (United Kingdom); Bottom: My wayfinding typeface

Figures are also crucial when a typeface is used for signage. In print typefaces the figures are mostly designed rather inconspicuously so they don’t stick out from the text. But figures in a signage typeface need to be very clear and easily distinguishable. The standard figures in my wayfinding typeface are tabular lining figures to accommodate the typical tabular use. But old-style figures (both proportional and tabular) are also available.

My wayfinding typeface also comes with a large set of arrows. They perfectly match the metrics and stroke withs of the typeface and can therefore be placed along with the text without any further corrections.

Moreover, the arrows can be used with some “OpenType magic“ built into the font. You can just type in certain letter combinations to automatically generate the arrows on the fly. (see demo below)

(Movie doesn’t work? Check it out at Vimeo…)

Positive and negative contrasts are often combined on one sign. Since light text on dark background always appears bolder, this can create an unwanted differentiation. A good signage typeface should compensate for this effect by offering different stroke weights to be used for positive and negative contrast.

Different stroke widths to be used for positive/negative contrast (only visible when the background is removed)

When I designed this typeface I usually had road sign in mind, but the typeface is not limited to this context. I can be used for all kinds of signage projects.

The typeface is not finished yet. I may extend the character set and add more styles. But designers working on wayfinding projects may contact me about a trial version of the typeface.

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The old Swiss traffic sign font is called SNV (“Schweizerische Normen-Vereinigung”). It is a very geometric typeface with obvious legibility problems.

The SNV fonts can still be found on older Swiss traffic signs and also in Belgium where it is still the main font on road signs.

Since 2003 a new font called ASTRA Frutiger is used. It is based on Frutiger 57 Condensed with slight changes.

ASTRA Frutiger is used in two styles: “Standard” for normal roads and “Autobahn” for motorways. The latter uses a slightly wider spacing.

Frutiger is of course a perfect choice for traffic signs. It was derived from a design by Adrian Frutiger for the signage of the Roissy Airport in France. The clean and open design of the letters make the typeface very legible and it became one of the most popular sans-serif designs in the 20th century.

Nevertheless there is some room for critique. The Frutiger typeface is already available in many different widths and weights, so it would have been no problem to obtain different versions for positive and negative contrast as well as styles with different widths. Choosing a condensed style as the main font could be problematic since a condensed style will always be slightly less legible than the corresponding style in the normal width. The official norm even allows the already condensed font to be further reduced in width. This is done without any typographic correction and decreases the legibility.

See also:

• Other traffic typeface articles
• Flickr pool Type of Traffic Signs

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The main typeface used in Italy is called Alfabeto Normale and is a bolder version of the British Transport alphabet. From its use in Spain it is also known as Carreta Conventional or CCRIGE and it is available as Traffic Type Spain from URW++.

A slightly thinner version is available for white letters on dark backgrounds. But nonetheless both version are way too bold for today’s retroreflective road signs. It’s easy to imagine how the details will get lost when those letters are viewed from a greater distance or when the sign is lit by headlights. This is also true for the condensed style called Alfabeto Stretto, which is also available for positive and negative contrast.

City names are always set in uppercase letters, but I usually didn’t had trouble reading them, since Italian city names are usually short and set in large sizes.

But the overall sign design has many problems. A typical mistake is not to limit the amount of information on the sign. One sign in Italy may present dozens of targets and additional information which are impossible to read even if you would slow down.

Road numbers are usually very hard to read, since they are scaled down to fit in a rectangle the size of the capital letters.

Another typical Italian problem I encountered was the missing continuity. You might follow a road (let’s say to Venice), but then hit a roundabout where this major target just isn’t listed for any of the available directions. And when it comes to Italian motorways you don’t get a chance to easily correct your direction, since they are all toll routes with very few exits.

In the northern part of Italy the signs are usually set in German and Italian, but a typeface borrowed from the U.K. obviously doen’t have German letters …

See also:

• Other traffic typeface articles
• Flickr pool Type on Traffic Signs

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The Netherlands are a special case when it comes to traffic signs…

Until recently the organization being in charge of the traffic signs was the ANWB. It was founded as a Dutch bikers(!) society (“Algemeene Nederlandsche Wielrijders Bond”) in 1883 and later became the royal tourist society.

In my opinion these roots are still visible in the design of the traffic signs. On local roads you will see a lot of these sign posts, which are certainly based on the old finger-post signs, used long before the invention of the automobile.

The typeface used since the 1960s is called ANWB-Ee (also RWS-Ee) and it is based on FHWA series E (Modified) from the United States. A condensed version (ANWB-Cc) is also available and it is based on the FHWA series C design.

In the late 1990s Gerard Unger was commissioned to design a new typeface called ANWB-Uu.

(source: designworkplan.com)

Mr. Unger’s task was to create a font which needs less space to fit the text on the smaller fixed-size direction signs. He achieved this goal. But in my opinion the the briefing itself was wrong. The size of a direction sign must be based on the content, not the other way around! What do you do, if you need to set Gasselterboerveenschemond on such a sign? On top of that, I found these sign posts often mounted at the most unfortunate places, for example behind traffic lights or far away and too high above the ground in the middle of a large roundabout, impossible to read.

By contrast on a local direction sign in Germany the type size is based on the maximum speed of the traffic at this point and the width of the sign will grow according to the content.

Recently the ANWB-Uu typeface is also appearing on the larger motorway (“autosnelwegen”) signs in the Netherlands, but using only a rather condensed typeface on large signs is usually not appropriate. It would at least need a corresponding version that is not condensed and can be used whenever there is enough space.

The layout of the signs could also be improved. The signs sometimes appear way too crammed…

or simple but pretty ineffective:

See also:

• Other traffic typeface articles
• Flickr pool Type on Traffic Signs

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In France four fonts are currently used. The main fonts are called L1 and L2.

L1 and L2 are caps-only alphabets. L1 is set in black letters on white background and is used for local targets.

L2 is set in white on blue (Autoroutes) or green (Routes Nationales) background and is used for distant targets. L1 and L2 are basically the same design, but L2 is lighter and set with increased spacing to compensate for the overglow effect of white letters.

The design of L1 and L2 are neither very good nor very bad. It’s a typical semi-geometric design similar to the traffic typefaces used in other European countries. A unique feature are the large counters of P and R. In general it is a good idea to have large counters for a typeface used for traffic signs, but a letter is also recognized by the white-space around it, so they might have overdone it a litte bit. Another problem might be the descenders of Q and Ç, which are designed not prominent enough.

For local target and public facilities the italic font L4 is used. The uppercase letters are similar to the L2 fonts and the lowercase letters bear resemblance to Frutiger’s Univers typeface.

In theory it sounds like a good idea to use different type styles to mark different kinds of targets, but when I look at the different styles and sizes in this image, the result looks rather confusing:

The same is true for the overall design of the signs on which the content looks very scattered. The color coding works fine, but the separated signs and the type treatments don’t give me any clues about a clear hierarchy of the presented information:

An additional font is the L5 alphabet. It seems to be derived from Frutiger and is apparently used for signs of less importance, for example the ones pointing to local points of interest.

A freeware version of L1, L2 and L4 is called Caracteres and can be downloaded from here.  URW++ offers a commercial digitization called Signal.

See also:

• Other traffic typeface articles
• Flickr pool Type on Traffic Signs

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When I first saw a digital version of the Polish traffic typeface, I though I must have gotten a really bad digitization. It had characters which were obviously cut off by mistake …

But I later found out that this is the way the typeface is supposed to look like according to the official specifications:

The typeface has a very simple geometric design almost without any typographic corrections. Only one style is in use. There is no condensed style available and no variations for positive/negative contrasts.

But Poland is a good example that type design isn’t everything when it comes to the design of traffic signs. The Polish signs compensate for the poor type design by making most of the information and direction signs very large, thus still achieving a good legibility.

Unfortunately, the typeface almost always fails when the type has to get smaller. See this next example on a motorway, which is supposed to be read at 110 km/h (70 MPH).

There are two digital versions available: Tablica drogowa by Grzegorz Klimczewski and Drogowskaz by Emil Wojtacki. The latter is freeware and I recommend using the TrueType version. The OpenType PS font has some outline bugs.

See also:

• Other traffic typeface articles
• Flickr pool Type on Traffic Signs

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The official traffic typeface in Germany is called DIN 1451 and has a very long history …

It goes back to the beginning of the 20. century when the Royal Prussian Railways (Königliche Preußische Eisenbahn) defined a new master drawing for the lettering for the description of freight cars, The typeface was later adapted for all kinds of signages of the German railways. In the 1920s major German industrial companies met to agree on all sorts of technical standardization including type standards. The result was called DIN 1451 and was based on the railway typeface. The typefaces were created on a very simple grid system and with a continuous stroke width. The type norm was published in 1936 and became a standard for traffic signs, road signs, street names, house numbers and license plates. Over the next decades the typeface also appeared on all kinds of goods and household articles, making it THE German typeface.

You can read the full story of the history of the DIN typeface in a series of articles by Albert-Jan Pool (designer of FF DIN) in the issues 13, 14, 15, 17 and 18 of the encore magazine.

East Germany

In East Germany the use of DIN 1451 was reviewed in the 70s. In tests with a tachistoscope Gill Sans performed better than DIN 1451 and so Gill Sans was used as the stadard traffic typeface in East Germany. They were certainly ahead of their time in choosing a humanistic sans-serif, but it is obvious that the spacing was way too tight for traffic signs. (But then again, East German cars couln’t go very fast.) When Germany was reunited in 1990 all signs in Gill Sans were replaced with new signs using DIN 1451.

DIN 1451 today

Today two revised styles with typographic adjustments are used. DIN 1451 Mittelschrift is the main typeface:

The condensed style (DIN 1451 Engschrift) should only be used when there is not enough space to use Mittelschrift.

Even in this improved design it is still apparent, that these fonts were never made for traffic signs and reading at high-speed in the first place. The weight and the tight spacing is only working well at a close distance.

FontShop offers an extended version of this typeface called FF DIN, which has become very popular for corporate design and advertising.

See also:

• Other traffic typeface articles
• Flickr pool Type on Traffic Signs

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Denmark is very generous with colors. Road sign can be red on white, white on green, blue on white, black on yellow and white on blue. Red (usually reserved for emergency icons) is the main color, because it is the color of the national flag of Denmark.

Between 1955 and 1978 a relatively light typeface with large ascenders and descenders was used (see first line in the above image). In 1978 a new typeface was approved by the Ministry of Transport (bottom line). It was taken over from the British Road Alphabet (“Transport”), designed by Jock Kinneir. The Danish letters æ,ø and å were added and a few details were adjusted. For example: the figures were made more open and the spacing was increased.

The typeface decides the size of the sign. The size of the typeface (cap height: 25–480 mm) is based on the speed of the cars and technical qualities like contrast and retroreflection. Since there is no condensed style available, signs can get very wide.

The Dansk Vejtavleskrift is used in two styles: “Positiv skrifttype” (for dark text on light backgrounds) and “Negativ skrifttype” (for light text on dark backgrounds). The latter has increased spacing, but no changes in weight.

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The swedish typeface for traffic signs is called Tratex and was designed by Karl-Gustav Gustafson and modified by Chester Bernsten.

Tratex is available in 4 styles. The first one is called Svart (“Black”):

Vit (“White”). It has an increased spacing to compensate the overglow effect.

PosVersal (“Positive Caps”):

NegVersal (“Negavite Caps”). Identical to PosVersal, but with increased spacing:

Swedish signs are mostly set in all caps. This seems to be a common practice in all Scandinavian countries.

Signs with lowercase letters seemed to be reserved for local targets and tourist information signs.

You can download the Tratex fonts from the website of the Swedish Road Administration (MacOS X Diskimage here). The quality of those fonts is really bad. There is also a version from URW++, but they only offer one style.

• Other Blog entries about traffic typefaces
• Flickr group Type on Traffic Signs

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