Dislosure of the invention The method of the invention comprises: forming blocks of rigid coloured material shaped as mosaic components of the road sign; composing the sign by arranging the blocks as a mosaic; incorporatedly inserting the blocks into the upper layer of the wearing course, in such a manner that the upper surface of the mosaic road sign is substantially coplanar with the road surface.

Its component blocks can be formed of material relatively resistant to the wear which occurs on the road surface by normal vehicle and people passage; in addition these blocks can be of many millimetres thickness and be coloured throughout.

Consequently by virtue of the invention, a road sign incorporated into the wearing course is formed, which can have a very long life under normal use of the road.

Moreover, the road sign formed can have a relatively high vivacity and brightness, and in any event greater than those of the usual road signs formed by being painted on the road surface.

The invention is described in detail hereinafter with the aid of the accompanying drawings, which illustrate a non-exclusive embodiment thereof.

Figure 1 is a perspective exploded view of the means of the invention.

Figure 2 is a view of the road sign from above.

Figure 3 is a section on the plane III-III of Figure 2.

According to the invention, blocks 10 of rigid coloured material are formed, shaped to enable the required road sign to be formed

by the mosaic technique.

The blocks 10 are of prismatic shape and are all of equal height; the geometric shape of their base determines the figure which is composed. This shape can be constant, or as shown on the drawings can vary from block to block, even within the same figure of the road sign to be formed, and is such that the blocks can be fitted together without creating noticeable gaps between one and another.

Figure 2 shows an example of a road sign indicating a"dangerous crossing".

The figure of this road sign is obtained by a plurality of blocks 10, the base of which varies in shape and dimensions; for example, it comprises: -various blocks 10a the base of which has the form of an equilateral triangle (these forming the peripheral part of the figure), -some blocks 10b with a square base (these forming the"X"), -some blocks 10a the base of which has the form of an isosceles triangle (positioned about the"X"), -and other blocks 10d, 10e and 10f, of different shapes, which surround the central figure.

Obviously this is only an example, it being apparent that the number of road sign figures which can be obtained is indeterminate and consequently the shapes and dimensions of the bases of the bases of the blocks 10 can be various.

In addition the colour of the blocks varies, to form a road sign composed of a number of colours. For example, in Figure 2 some blocks 10a are of one colour, whereas other blocks 10a are of another colour.

Advantageously, the blocks 10 are formed of fired ceramic, in particular by the method used to form porcellainized ceramic stone tiles.

In particular, the blocks 10 are of ceramic material coloured throughout.

In the embodiment shown in the figures, a pan-like container 20 is provided, of prismatic shape with a relatively large base 21 and relatively low vertical side walls 22, but without a lid. The

container 20 is arranged to contain, substantially as an exact fit, the road sign composed in mosaic form by the blocks 10; in particular its base 21 is substantially equal to the shape of the entire road sign, except for a slight clearance, and its side walls have a height virtually equal to the height of the blocks 10.

In addition, again in the embodiment shown in the figures, a second pan-like container 30 is provided to contain the first pan- like container 20 substantially as an exact fit (with slight clearance), and to be immersed into the upper layer of the wearing course (Figure 3). In particular, the second container 30 has a base 31 of the same shape as but slightly wider than the base 21; its vertical side walls 32 have a height virtually equal to the walls 22 of the first container 20.

One embodiment of the method comprises incorporatedly inserting the second container 30 into the upper layer of the wearing course, so that the container cavity remains empty and faces upwards.

Typically, the container 30 can be inserted into a cavity 41 formed in the upper layer 40 (of asphalt or equivalent material) of the wearing course. The cavity 41 has a width slightly greater than the outer dimension of the second container 30; after this has been inserted into the cavity 41, filling material 42 (adhesive-based or the same asphalt forming the layer 40) is applied to close the cavity about the container 30 such that this remains embedded in the layer 40, with its upper edge substantially coplanar with the road surface.

Preferably the container 30 possesses suitable lugs 34 to enable it to better grip the material in which it is embedded.

The blocks 10 are firstly inserted into the first container 20 and composed as a mosaic to form the road sign. They can be inserted dry, or can be glued to the base 21 by an adhesive layer 24 (see Figure 3); or they can be glued together by adhesive inserted between one block and another. This insertion of the blocks 10 into the containers 20 can obviously be advantageously done in an appropriate factory equipped for this purpose.

The container 20 containing the mosaic road sign is then taken to its place of application and is inserted into the second container 30, taking care that the upper surface of the mosaic road sign is substantially coplanar with the road surface.

In this manner a road sign is obtained inserted into the wearing course, as a component of the wearing course itself.

Moreover this road sign is formed of a material which is highly resistant to wear and hence long-lasting.

Furthermore, given that the blocks are coloured throughout, the figure formed by them lasts until the entire thickness of the blocks has been worn away; and as this thickness can be some centimetres in practice, the resistance to abrasive wear of the road sign formed in this manner is practically infinite.

Again, as the road sign is composed of several blocks 10 associated with each other but slightly movable one relative to another, the road sign is at least slightly deformable under the stress of the passing vehicles, and hence advantageously, in response to this stress, has the same behaviour as the wearing course.

The container 30 remains permanently incorporated into the wearing course, and serves essentially as the base for the first container 20. This can be extracted from the container 30, together with the road sign, for repair or replacement.

Alternatively, the second container 30 can be dispensed with. In this case, the container 20 together with the mosaic of blocks 10 is embedded directly into the upper layer of the wearing course, such that the upper surface of the road sign is substantially coplanar with the road surface.

As a further alternative the first container 20 can be dispensed with. In this case the blocks 10 are embedded directly into the upper surface of the wearing course, again such that upper surface of the mosaic road sign is substantially coplanar with the road surface.

Numerous modifications of a practical and applicational nature can be made to the invention, but without leaving the scope of the inventive idea as claimed below.