Road Sign Symmetrical Narrowing Triangle Side 90 cm Class 1 Fig. 17 Iron

The Symmetrical Bottleneck Sign: Safety and Clarity on the Road

The "Symmetrical Bottleneck" road warning sign, identified by Figure II.17 of the Highway Code, is an indispensable element for vehicular safety. Designed to warn motorists of an impending narrowing of the roadway on both sides, this sign helps prevent potentially dangerous situations, especially in heavy traffic, curves or limited visibility. Its installation is crucial to guide users to a more cautious driving behavior, reducing speed and increasing attention to side spaces.

Technical Characteristics and Materials

This triangular sign, with the vertex facing upwards, is made of resistant boxed iron sheet with a thickness of 10/10 mm, ensuring strength and durability over time. The standard size of Lato 90 cm makes it ideal for a wide range of contexts, from urban environments to secondary extra-urban roads. Class 1 (RA1) reflective film ensures standard visibility in different light conditions, particularly effective in urban or otherwise well-lit areas. The design includes a white background, a bright red border and a black pictogram representing two converging, clear and immediately recognizable lines. It complies with the UNI EN 12899-1 standard for permanent vertical signs, synonymous with reliability and compliance with current regulations.

Function and Importance for Circulation

The "Symmetrical Bottleneck" sign plays a fundamental role in managing the vehicular flow and increasing safety. Announcing the narrowing, this sign:

It limits the possibility of overtaking in critical sections. It requires a reduction in speed to tackle the stretch safely. It encourages greater attention to the side dimensions of vehicles. It reduces the risk of collisions between heavy or generously sized vehicles.

It is particularly recommended in areas such as mountain roads, sections with mobile construction sites or barriers, and near narrow bridges or arched crossings, where the roadway narrows significantly.

Installation Guide and Regulatory Compliance

For optimal effectiveness, the sign must be installed at a regulatory distance before narrowing, which varies according to the maximum speed allowed on the road. Standard mounting involves the use of a Ø48 mm galvanized round pole, with a recommended height of the lower edge of the signal from the ground between 2.20 and 2.50 meters. Compliance is guaranteed by the Highway Code (Art. 39) and the Implementing Regulation (Figure II.17), as well as the UNI EN 12899-1 technical standard for permanent vertical signs. Class 1 (RA1) of the reflective film allows it to be used in urban areas or with adequate lighting, providing sufficient visibility for day and night signaling.

Frequently Asked Questions about Symmetrical Bottleneck Signal

What is the "Symmetrical Bottleneck" sign?

It is a danger sign (Figure II.17) that warns motorists of an imminent narrowing of the carriageway on both sides, requiring caution and speed reduction.

What are the dimensions and material of this signal?

The sign has a triangular shape with a side of 90 cm and is made of boxed iron sheet. The reflective film is Class 1 (RA1).

Where is the installation of the bottleneck sign recommended?

It is particularly useful on mountain roads, construction sites, narrow bridges or arched crossings, and in general in all sections where the roadway narrows on both sides.