Differentiation of languages in sign design
Bilingual ‘time delay’…
Wales’ bilingual solution takes longer to read than a one-language sign (Rutley 1972). This is not surprising, because increased information on a sign increases comprehension time. And the time is increased further, especially for English-speaking drivers, when Welsh is placed above English.
It does suggest the importance of differentiating our Irish place names from the English. In view of the status of the Irish language, how is a level of differentiation best achieved, whilst preserving ‘equal prominence’? 
Above: Welsh/English sign
Differentiation in dual-language signs in Wales
Above: Dual language sign, Wales.
In Welsh road signs no visual differentiator is provided between the languages. In part, the aim of this is to afford Welsh equal prominence. Welsh may be placed above or below English (at the discretion of the local council) in the same weight of Transport. The theory here is that users, having familiarised themselves with the arrangement over an initial number of signs, automatically seek the language of choice – i.e. if English, the place name will appear on the second line. Whilst the UK DoE tested a number of options at the time and this was deemed the most favourable solution. It did not factor the occurrence of long place names.
Above: A long place name may run to two lines, the second line being slightly indented. Author’s illustration.
In the case of a long name, whether in English or Welsh, the place name runs to two lines on the sign. The second line is indented slightly. This may in fact confuse the driver. i.e.. Is this new line a new place name? If it is misunderstood as such, the reading-order of a driver (who has ‘learned’ that the next line will be the second language) is confused. In the initial DoE tests, samples made available in the report, show such long place names being tested (Rutley 1972). Later, in further testing (Rutley 1974) longer place names were indeed used, but no such indent is shown, presumably this was added at a later date.
Above: Welsh road sign test from the Transport and Road research Laboratory – used an extreme method of differentiation, described as ‘Welsh in the same script but in a different colour from the English’. (Rutley 1974)
I believe a secondary colour would have yielded better test results. While the Welsh earlier tests did attempt a colour variant, each Welsh word was rendered reversed out of a dark background. This perhaps had the effect to over-emphasise and distract. Unsurprisingly, the report states that this sign type did not perform well. It is possible that the technology and cost of producing the signs in the early 1970’s would have led to this unusual solution being proffered in place of a straightforward secondary colour, this would no longer be an issue. Whatever shortcomings the Welsh system may have, it has been well tested – and the goal of representing Welsh as equally important to English has certainly been achieved. As with any bilingual sign – this has an effect on the performance of the sign.
In Ireland, I believe lessons learned in Wales could be put to use in creating a more efficient system for all road users – and which delivers the government’s aim of equal status for Irish. It is possible that colour differentiation could help accomplish this.
Above: Language differentiation using colour is accepted practise at airports. (Simulation of the Swedish airport design)
Examples of colour used for language differentiation…
Other countries have used a colour differentiation technique with some success. Similar design solutions can be found in international airports (Figure 34). From a design point of view, there is enough here to give grounds for confidence that in the right hands a successful design solution utilising colour can be achieved. It is perhaps no coincidence that the use of the yellow (route) colour is amongst the more successful of these solutions, as this is consistent to what we see in airport use (Figures 35 & 36).
Above: Dual language road sign, Greece. This sample illustrates effective use of an existing sign colour (route yellow) as the differentiator. Photo: Dr Pádraig Ó Laighin.
Above: Dual language road sign, Scotland. This bilingual sign uses the UK system but with the addition of colour as a differentiator. Photo: Owen Blacker.
Above: Dual language road sign, Scottish Highlands. Photo: Ewen Denney.
What about Colour ‘blindness’? (Colour deficient vision)
When colour is raised as a design solution, it is inevitably scrutinised in terms of implications for colour-blind individuals. The following signs (Figures 38-40) demonstrate the effects of colour deficient vision on a current national route sign. Figure 40 (overleaf) shows the most common (red) deficiency. Approximately one in twelve men has some degree of colour deficient sight (Rigden 1999). Aging is also a factor, with colour deficiency increasing proportionally with age.
If, based on experience and these tests, we assume that existing road signs colour schemes are without significant issues; using an existing sign highlight colour will necessitate no further testing for colour blindness. Use of any new colour combinations would require further testing.
Sign sample filtered for colour deficiency
Above: A standard green background national road sign - filtered for Deutoranope (green deficient) colour deficiency.
Above: Standard green background national road sign – filtered for Tritanope deficiency (yellow deficiency). It’s interesting that this ‘becomes’ a blue motorways sign.
