Mott MacDonald found that, on the basis of a preliminary and high level review, the tunnel could be built and may be economically feasible.
The consultant has estimated a range of costs from €156m for a single-bore three-lane bi-directional tunnel to €1.08bn for a twin-bore two-lane uni-directional tunnel.
In July 2011, Transport Malta appointed Mott MacDonald to carry out a preliminary analysis of road tunnel link options between Malta and Gozo. The assignment was secured as part of the EU JASPERS programme of technical assistance to Malta.
The purpose of the five-month study was to provide a list of technical, engineering, environmental and economic issues relating to potential sub-sea tunnel fixed-link options connecting Malta and Gozo. The study presents a high-level analysis of different tunnel options based on existing data, studies, information, site visits and various discussions with stakeholders.
The final report presents a background review and a list of key issues identified during consultation with the various stakeholders. It provides a broad economic assessment of introducing a fixed link between Malta and Gozo and identifies four potential tunnel alignments for further investigation. It also presents a high-level environmental assessment of each of the four tunnel route alignments.
The number of vehicles crossing between Malta and Gozo increased at 4.1% per annum between 2000 and 2010. In 2010, there were an average of 1,500 vehicles per day /direction and 5,500 people per day/ direction travelling between Malta and Gozo.
The introduction of a fixed link would reduce average journey times between Gozo and Malta by at least 40 minutes.
The four potential tunnels alignments range in length between 6km and 10km. The options take into account the engineering and environmental constraints that Mott MacDonald was able to identify using existing data and information.
A detailed geological and geotechnical investigation is still required to determine more precisely the tunnel alignment, tunnel form, cost and construction methodology.
Mott MacDonald has estimated costs for the construction of the four different tunnel option alignments based on a case history review of different tunnel types around the world. The range of costs estimated for the construction of the fixed link is wide and would depend on ground conditions and other circumstances.