Brazzaville–Kinshasa Bridge

The Brazzaville–Kinshasa Bridge is a proposed road-rail bridge planned to connect Brazzaville in the Republic of Congo and Kinshasa in the Democratic Republic of the Congo, which are large cities astride the mighty Congo River that are capitals of their respective countries.^[1]^[2]^[3]

The bridge would need to be about 4 km long.

Advantages

Amongst other things, the proposed bridge would connect Kinshasa via rail to the deepwater 10.46m draft port at Pointe Noire ^[4] rather than the shallower 8.20m draft river port at Matadi.^[5]
The railway systems of both countries use the same gauge, namely 1,067 mm (3 ft 6 in)
With ever bigger ships, shipping companies prefer to use fewer ports.
The connected railways can share rolling stock which saves capital costs.
If one line is closed, for example by floods, traffic can be diverted to the other line.
There are potential lines from Angola and Namibia which would create a better network.

A minor detail would be to eventually unify couplers and brakes, etc, if not already compatible.