InfrastructureUnder-road heating system to keep Europe’s highways ice-free

By Rex Merrifield

Published 4 February 2019

Snow and ice can dramatically change the conditions of a road, where slippery surfaces make it harder to keep control of a vehicle, particularly when braking or turning. Under-road heating that melts ice and snow within 15 minutes and real-time information about icy road conditions could help prevent wintertime accidents.

Snow and ice can dramatically change the conditions of a road, where slippery surfaces make it harder to keep control of a vehicle, particularly when braking or turning.

‘Once you have cars driving, the dynamics of the ice and snow change (because of the movement of the vehicles), and in a place such as a highway exit, the (risk of) injuries or fatalities goes up,’ said Yonatan Elimelech, a partner at Israeli-based engineering firm SAN Hitech Ltd.

A project called Snowless, which Elimelech coordinates, has developed autonomous ice-melting technology for roads and pavements, using a mesh of metal ribbons embedded in the asphalt or concrete surface.

Sensors monitor temperature changes in the surface material, combining this data with forecast weather conditions and information about the power required to heat the ribbons. By automatically switching on the strips when needed, the system can prevent ice and snow from forming or rapidly eliminate them. It also replaces harmful de-icing materials such as salt, which can damage infrastructure including iron bridges over the long term, grit or toxic anti-freeze chemicals like ethylene glycol.

The 25mm-wide elements are produced with a metal alloy that provides rapid heating when an electric current is passed through it. The ribbons absorb little heat themselves, but radiate warmth to typically melt problem ice within 15 minutes.

It can also operate at lower temperatures, down to as cold as -50°C, such as in Canada, where the system has already been used successfully.

The system has been used on smaller roads, as well as parking lots and pavements, and has even shown its worth in de-icing sports fields. Other places that can benefit are taxi ranks and airports.

Snowless is currently optimizing its algorithm for use on roads carrying heavier traffic. Elimelech said it had shown to be well suited to use on bridges and highway exits, which are particularly hazardous in poor weather conditions.

For a new road, the heating elements and sensors are unrolled in a mesh and the asphalt or concrete is then poured on top. For existing roads, a grooving machine cuts slits into the surface, into which the ribbons can be inserted.

The system’s ability to react instantaneously to changes in weather contributes to its low energy consumption, according to Elimelech.