We are now used to reading road signs very little, especially on motorways, where most of the information refers to directions or information relating to traffic and road conditions in general. Nowadays, in fact, all this information is managed via our smartphone and the use of dedicated applications for route tracking anywhere in the world. We therefore automatically know which direction to take and where we might encounter traffic (or even an accident!). However, being aware of the main road sign systems remains useful and allows for greater driving confidence. What is the main signage used on the motorway network and what are the technical and geometric requirements that it must comply with?
Types of signs
There are different types of road signs, mainly divided into
- Horizontal signs;
- Vertical signs.
These two types are joined by luminous signs and all complementary signals and equipment. The Highway Code differentiates the use of elements belonging to these categories and it is clearly a violation of the law not to respect the instructions given on them. Vertical signs are divided respectively into three macro-categories, which contain signs of:
- Danger;
- Prescription;
- Indication.
On the other hand, horizontal signs do not contain information relating to dangerous conditions but rather regulate circulation and guide users in the behavior to follow, sometimes introducing prescriptions. A peculiarity present on the motorway is certainly linked to the traffic islands when there are intersection points. In the connecting strips there are therefore white stripes, inclined at least 45 degrees. The zebra pattern provides a safety margin in the maneuver with respect to the presence of the precise intersection between the lanes, guaranteeing greater usability of the infrastructure.
Some motorway peculiarities
As with all types of roads, we also have to deal with these types of signs on the motorway. The horizontal one is rather repetitive and not very articulated, as it aims to distinctly identify the lanes of the generic carriageway and the extension of the latter. We are therefore mainly dealing with longitudinal striped signs (i.e. directed along the development of the motorway). In the intersection areas, i.e. where there are entrances or exits from the main direction, we find traffic islands
As regards vertical signs, however, different measures are taken in the introduction of these elements along the route, in relation to the higher travel speeds, if compared with road types of lesser importance). What are these precautions? Mainly two:
- we are dealing with larger signs than those found on less important roads;
- we are dealing with positionings repeated more frequently (relative to the point we want to indicate) if we are dealing with roads of less importance.
As regards dimensions, however, signs are used that exceed one meter on the side of the generic rectangle that identifies them. We can therefore also find ourselves with scoreboards of several square meters. Some of these are “hung” on large steel structures that cross the motorway carriageways. These represent accessory motorway works, not present on roads of modest importance. Furthermore, variable message panels can be housed on these structures. The peculiarity of these elements lies in the fact that they can report instant information on traffic, information relating to the presence of queues or any accidents. Then, all this information can dynamically evolve over the course of the day, giving the driver valid information precisely at the moment in which he is traveling along the route.
Let’s take an example: to report a danger it takes 150 m, regardless of the type of road. That is, I must have a danger sign 150 m before the actual danger. However, on the motorway there is a need for more sighting space, which means that the sign must be larger. The sighting space goes from 50 m for minor roads, 100 m for secondary extra-urban roads and up to 150 m for motorways. It means that at 150 m the driver must have clear visibility of the signal. Similarly, a prescription must be sighted 250 m before on motorways, 150 m on secondary extra-urban roads and 80 m on all other types. Below is a graph showing the reference values of the distances as the travel speed varies:
Since the motorways are one-way traffic, with a reversal permitted only after exiting the current direction of travel, each motorway section is equipped with a so-called confirmation signal. It represents a particular type of signal that is inserted when passing complex intersections, or when leaving a main location. After the end of the acceleration lane (for entering the current section), about 500 m from it, there is a confirmation sign. What is it for? It allows the driver to be immediately aware of the direction chosen and to correct it promptly in the event of an error.
Speed control signs
Much of the Italian motorway network has an electronic speed control system, necessary to ensure compliance with safety regulations. The control devices must be indicated in their actual position, always using appropriate signs. Not only that: along the route the driver must be informed of the presence of the speed control system, before arriving precisely at the reading point.
The toll stations
Toll stations are markedly indicated on the motorway section. This is a safety measure associated with the natural decrease in speed expected at the toll booths and a possible traffic jam generated by the consequent reduction in speed of a large number of vehicles. This signal is also associated with requirements relating to speed reduction compared to the standard travel sections, as can be seen from the figure below.
The use of coloring in road signs
As is known, road signs have a standardized color that cannot be changed by the managing body at will, which therefore must comply with the indications of the reference regulations, such as the highway code. Everything relating to motorway signs is indicated in green. This is true both for indications within the motorway, or to indicate a possible directional departure to it but on roads of lesser importance. If green is the background used, the internal writings and symbols on the background color cannot be arbitrary: in the motorway case we have white as the reference colour.
