Elon Musk built a tunnel company over LA traffic

Why Put a Road Beneath the Road?

A tunnel seems to create a second route without taking space from buildings, sidewalks, or surface streets. That was the appeal behind Elon Musk’s Boring Company: instead of widening roads through Los Angeles, dig passages below them and move vehicles out of the surface traffic stream.

But underground space is not automatically a faster transportation system. A tunnel needs entrances and exits, and every vehicle still has to reach them. If cars queue at a portal or merge back onto a crowded street, the bottleneck has moved rather than disappeared. The route works best when the underground section connects places people need to reach and the access points can handle demand.

The Hard Part Is More Than Digging

Building a tunnel means moving enormous amounts of earth while avoiding existing foundations, pipes, cables, and other underground infrastructure. The deeper and wider the passage, the more excavation and construction it generally requires. Smaller tunnels can reduce that burden, but they also limit what can travel through them and how much traffic they can carry.

Tunnels also need systems that ordinary roads do not: lighting, drainage, emergency exits, and ways to manage smoke and evacuate people if something goes wrong. Those requirements make safety and operations part of the design from the beginning, not details to add after the boring machine finishes.

A New Route, Not a Cure for Congestion

The company’s underlying wager is that faster, less costly tunneling could make underground routes practical in places where surface expansion is difficult. If a tunnel moves only a modest number of vehicles, however, it may offer a useful shortcut without changing traffic across a whole city. The key question is not simply whether a tunnel can be dug, but whether its entrances, capacity, and connections move enough people to justify it.

That is the tradeoff beneath the pitch: underground roads can bypass the contest for asphalt above, but they still have to connect to the same crowded city at either end.