The Erjos tunnels are taking shape beneath the mountains of western Tenerife, with work now focused on waterproofing and installing service walkways inside the two parallel tunnels.
Each tunnel measures 5.1 kilometres, and once completed, they will be the longest road tunnels in the Canary Islands. It’s a major engineering project, designed to make travelling between the north and south of Tenerife considerably quicker.
Francis González, Deputy Minister of Infrastructure for the Canary Islands Government, recently shared a video showing the progress of the work. He noted that visitors who get the chance to tour the tunnels are often surprised by their sheer scale and complexity.
A Much Quicker Journey Across the Island
The tunnels form a key part of the western section of the Tenerife Ring Road, an 11.3-kilometre route connecting Santiago del Teide in the south with El Tanque in the north.
At present, the journey between the two areas can take around 25 minutes in favourable conditions. Once the new road opens, that could fall to between seven and ten minutes.
The tunnels will have a maximum speed limit of 80 km/h and will accommodate a height difference of around 150 metres between their entrances.
The new route is also expected to offer an alternative to existing roads, potentially helping ease congestion around the metropolitan areas of Santa Cruz de Tenerife and La Laguna.
Initial estimates suggest the road could carry almost 17,000 vehicles a day during its first year, rising to as many as 30,000 later on.
Safety Work and the Final Stages
The current work includes waterproofing the tunnel linings to prevent groundwater from getting inside, alongside the installation of walkways to allow maintenance crews and emergency teams to move through the tunnels.
Safety features will include 19 cross-passages, spaced roughly 500 metres apart, as well as ventilation, lighting and communication systems. All these systems need to be completed and tested before the tunnels can open to traffic.
The project has a budget of €288.7 million, with more than €202.2 million already invested. Construction began on 25 November 2019, and tunnelling started in October 2020.
The excavation work has reached the ends of both tunnels, with the remaining work now focused on completing the infrastructure and making it ready for use.
The Canary Islands Government is targeting completion in the first quarter of 2027, subject to the remaining works and safety checks.
Solar Power and Environmental Restoration
The project also includes measures intended to reduce its environmental impact.
A planned solar photovoltaic plant with 936 panels is expected to supply around 55% of the tunnels’ electricity needs under normal operating conditions.
Work is also underway to restore old quarries using material excavated during construction, helping limit waste and improve the affected areas.
For anyone regularly travelling between Tenerife’s north and south, the Erjos tunnels could make a noticeable difference. The road still has work to get through before opening, but the project is moving towards a connection that should make crossing the island a good deal less time-consuming.