What are these bridges doing here?

China is pushing the boundaries of transportation with its Maglev (magnetic levitation) trains, currently experimenting with speeds of up to 623 km/h—200 km/h faster than the high-speed trains already in use across the country. Chinese scientists are even predicting that a future super Maglev train could reach a mind-blowing speed of 4,000 km/h, potentially breaking the record set by the SR-71 Blackbird jet at 3,529.6 km/h in 1979. As China advances its technology, there are also ambitions to connect Asian countries through a continent-spanning high-speed rail network.