PROJECT · TRANSPORTATION & HIGHWAY
The Proposed 4th Mainland Bridge
A 38-kilometre crossing from Ajah through Lekki and Baiyeku to Ikorodu — the largest single piece of transport infrastructure Lagos State has attempted.
CLIENT
Lagos State Government Office of Public-Private Partnerships
LOCATION
Ajah – Lekki – Ikorodu across the Lagos Lagoon
SCALE
38 km · 2 × 4 lane carriageway
STATUS
Preferred bidder appointed 2023
Lagos has three crossings between the mainland and the island. It needs a fourth.
The Fourth Mainland Bridge runs from Abraham Adesanya in Ajah, through Langbasa in Lekki and Baiyeku, across the Lagos Lagoon to Itamaga in Ikorodu. Procured by Lagos State through its Office of Public-Private Partnerships, it has been valued at around US$2.5 billion.
A crossing of this length is not really a bridge problem. It is a question of what the corridor does to land use, to demand on the existing three bridges, and to the economics of every journey it shortens.
Our role
Corridor and demand assessment
Modelling the diversion effect on the Third Mainland, Carter and Eko bridges, and the induced demand the new corridor generates on both shores.
Route and interchange appraisal
Comparative assessment of alignment options across the lagoon, and interchange arrangements at Ajah, Langbasa and Itamaga.
Geotechnical and marine assessment
Ground and lagoon-bed conditions along the alignment, and their implications for foundation type and cost.
Economic and PPP appraisal
Whole-life cost, toll revenue sensitivity and the structuring questions a concession of this size has to answer.
Have a project that has to work?
Tell us the constraint you cannot design around, and we will tell you how we would approach it.