If you have ever had to drive or pass near a highway in Italy, Belgium, Switzerland and many other countries in Europe, you will have noticed something curious: the road signs are not blue, but green. This is something that I was always curious to know why a few years ago, and there is more to the story than it seems. And it is the result of a series of historical and cultural decisions that each country made separately when developing its high-capacity road network.
The origin of the “problem.” Europe has had a common road signaling system since 1968, when the Vienna Convention on Road Signs. This treaty unified the shapes, symbols and many traffic rules, but left each country free to choose the colors of the orientation signs.
The agreement establishes that road markings can be white or yellow, and that pictograms must be internationally recognizable, but does not impose a single color for highways. Therefore, even if you drive throughout Europe under more or less similar rules, the colors of the signs change depending on the country.
Image: Maps Interlude
Why Spain chose blue. When Spain began to develop its network of highways and highways in the 1970s, it decided to use blue for high-capacity roads and white for conventional roads. This choice responds to a series of practical criteria: blue offered good night visibility with the reflective materials available at that time. Just like Spain, other countries also decided to opt for this color.
The green in other countries in Europe. Many other European countries opted for green for their highways. Belgium, Finland, Croatia, Italy, Switzerland, Ukraine, and many other countries have green signage on their highways. The decision has roots in the continent’s early highway systems. The first two major highway networks were the germans (Autobahnen) and the Italian ones (Autostrade), which used blue and green signals respectively.
The Italian choice of green probably influenced other Mediterranean and Eastern European countries, while the German scheme remained very consolidated and was imitated directly or indirectly by countries close to or with strong German technical influence.
Image: Luigi Chiesa
Nor is there one color better than another. Although you might want to start a war and choose sides between countries that use blue or green on their road signs, none is really better than the other. In fact, the main reason why both colors coexist on the continent is because they have not been standardized at the European level.
In this sense, both colors fulfill their function perfectly if they are applied consistently within each country. Blue stands out well at night, while green is very legible during the day and is psychologically associated with progress and continuity. As long as each driver can quickly identify what type of road they are using and it can be read clearly and without problem, all good.
What is unified. Although the colors vary, the Vienna Convention guarantees that a driver perfectly understands the signs whether he is in one country or another, because the pictograms, shapes and logic of the system are common. Triangles warn of dangers, circles prohibit or oblige, and rectangles inform. This harmonization is what really makes it possible to drive around Europe without having to study every national code.
If there are changes, it will not be in the colors. In 2025, the Global Forum for Road Traffic Safety launched a proposed amendment which could completely modify the text of the Vienna Convention, including new numbering for all signs. What will not change are the colors on the road signs, so each country will continue to have free rein to maintain its tradition. First because it works, and second because we are already used to it and that on the road means saving a lot of time.
Cover image | Google Maps
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