CO and NO2 detection and air quality control in tunnel.
The Gerediaga-Elorrio section starts in the connection with the AP-8 highway near Gerediaga, in the town of Abadiño. It goes on up to the western part of Elorrio where, through a new connection, it connects to BI-632 road, giving continuity to the Elorrio turnoff. It has a total length of 6.44 Km, with two-lane separate roads throughout its itinerary.
A large part of the route passes through tunnels. The tunnels of Gaztelua I and II include two tubes and have a length of 594 m and 1,141 m respectively. Between both is located the artificial tunnel of Gaztelua, 216 m long. Also, there is the cut-and-cover tunnel of Atxondo, with a total length of 95 m.
These tunnels are protected with CO and NO2 detectors designed and manufactured by DURAN ELECTRONICA and by anemometers and luxmeters distributed by DURAN ELECTRONICA.