U33 Temporary Sign – Alternating Traffic Section Ahead (Right), 150x120 cm, Class I

U33 Temporary Sign – Alternating Traffic Section Ahead (Right), 150x120 cm, Class I

The 150x120 cm panel with the words “Pericol de accidente” (accident danger), announcing from 400 m a section where traffic takes turns, controlled by signs, with class I retroreflective sheeting; the narrowing is on the right.

When class I is used

Class I (RA1) retroreflective sheeting is the basic class in SR 1848-2, with a 7-year service life. For roadworks, the standard requires temporary signs to have at least the class of the permanent signing on the section, so the class I version is used where the existing signs are class I too, typically on county and local roads and on streets without strong lighting. For national roads, lit boulevards or sections signed in class II there is the U33d_II version.

Where it goes, under SR 1848-1:2024

It goes on roads where a section with alternating one-way traffic, controlled by signs, must be announced. For alternating traffic controlled by traffic lights, the standard has a separate panel, the U34. On this panel the narrowing is on the right, and the distance to the section is 400 m.

What the roadworks rules require (Order 1112/411/2000)

The sign belongs to the advance signing, which is installed first, ahead of the work zone in the direction of travel, with at least 50 cm of clear space outside the carriageway. The rules require signs to be stood on the ground first, to check that they are clearly visible, and only then fixed to a support; no more than two signs go on the same support or side by side, and on one-way roads or bends they can be repeated on the left side or above the road.

For alternating one-way traffic, the rules allow three systems: priority signs, traffic marshals (with paddles such as the V12-20) or traffic lights for automatic control (for example the V11-20 portable lights), supplemented with priority signs. The system is chosen by traffic volume and the length of the section; alternating traffic cannot be organised on a work section longer than 1,200 m, and control by priority signs alone requires visibility between the two ends of the works.

On public roads, works are signed under the methodological rules approved by Order MI/MT no. 1112/411/2000. The road closure or traffic restriction is approved by the road authority, with the traffic police's agreement, on the basis of a signing layout endorsed as final, a copy of which the contractor keeps at the work site. The contractor installs, completes and maintains the signing for the whole job, removes it at the end and restores the original signing; accidents caused by incomplete or missing temporary signing are entirely the contractor's responsibility.

At night, if the existing signing on the road is retroreflective, the temporary signing must be retroreflective too and can be supplemented with flashing or sequential (“cascade”) amber lamps; on main and connecting streets in towns, retroreflective temporary signs are supplemented with flashing amber lamps.

Technical data

• 150x120 cm yellow panel with the words “Pericol de accidente”, the roadworks and road narrows on the right signs, and a distance of 400 m;
• 1 mm galvanised steel sheet, with rounded corners and pressed edges, no sharp edges;
• electrostatically painted;
• class I retroreflective sheeting (RA1), with a 7-year service life;
• fixings included: 4 clamps for Ø48 mm posts and 8 bolts with nuts;
• compliant with SR EN 12899-1:2007, SR 1848-1:2024, SR 1848-2:2011 and SR 1848-3:2011.

Mounting and size

Fixings for the post are included: 4 clamps for Ø48 mm posts and 8 bolts with nuts; clamps for Ø60 mm posts are available on request. The bottom edge of the sign goes 1.50–2.50 m above the road or kerb, and the edge nearest the road 0.50–2.0 m from the road platform.

SR 1848-2 sets a single size for this panel, 150x120 cm; the class II sheeting version, the same size, is the U33d_II.