The Smarter Bridge is a project led by Mix3d, which makes robotic 3D printers that can sinter stainless steel structures and inch their way along the surfaces as they are completed.
The final product will be a 12m pedestrian bridge in Amsterdam's red light district; the bridge will be studded with sensors that stream continuous telemetry about the load stresses and health of the structure.
The idea of a self-building bridge is an old challenge in computer science: in 1999, Brandeis's Dynamical and Evolutionary Machine Organization demoed a self-building bridge plan created using genetic algorithms that designed a way of adding and removing legos to keep the structure intact while it was in a partially built state.
The Smarter Bridge will be built in 2019.
A Smarter Bridge [Mix3d]