The world’s 20 largest tunnel construction projects account for $538.11bn of investment, spanning rail, roads, water infrastructure and energy. Yet the balance of spending is becoming increasingly one-sided. Railway tunnels account for 14 of the 20 projects and $383.17bn of total investment, or just over 71%, leaving every other sector competing for a much smaller share of the market.
Japan’s $72.27bn Tokyo to Osaka Maglev Railway Line: Tokyo to Nagoya Section tops the ranking, followed by the UK’s $65.99bn Hinkley Point C Nuclear Power Station electricity transmission tunnels. China’s $57.7bn Gwadar to Kashgar Railway Line and $47.19bn Sichuan-Tibet Railway: Ya’an-Nyingchi Section, together with the UK’s $45.43bn High Speed 2 Rail Link, complete the top five and reinforce the scale of investment flowing into strategic rail infrastructure.
The concentration becomes even more striking further down the ranking. Metro schemes in Australia and Vietnam sit alongside intercity rail links in France, Malaysia and India, while major road, water and energy tunnels appear only occasionally. The $30bn Countywide Stormwater Conveyance Tunnels in the US, the $20.1bn Sacramento to San Joaquin River Delta Conveyance System and New Zealand’s proposed Additional Waitematā Harbour Crossing are among the few projects that break rail’s grip on the list.