How sustainable and resilient could Hyperloop be?

This post is adapted from a post on Hyperloop One’s blog.

We often say walking and biking are the most sustainable forms of transportation. They are definitely low-emission and good for fitness. But I’m not sure I know anyone, except for a few crazy friends, who thinks a bicycle can replace the car or the airplane.

I am writing this while sitting on a “high-speed” train from Washington, D.C. to New York City, traveling at more than 100 mph. That makes it faster than a car or bus but slower than an airplane. This big train, Amtrak’s Acela Express, runs on electricity, and it takes a lot to move it up and down the East Coast. As the grid gets greener each year, it could, theoretically, become carbon neutral if the power generation were sustainable. My other choices for inter-city trips of less than 300 miles are a car, bus or airplane. Compared to those, based on current technology, this train is a greener choice.

But today’s high-speed trains have a physics problem called friction. The train experiences two types of friction: rolling resistance from the steel wheels on the rails and air resistance or drag. Drag is, well, a drag, because it increases with speed and makes very high-speed trains less energy efficient. High-speed trains in France (TGV), Germany (ICE), and Japan (Shinkansen) spend a large portion of their energy overcoming this friction problem at speeds over 200 mph. Even the most streamlined shape does not put a big dent in the energy costs of air resistance. Ever wonder why planes fly at 35,000 feet? It’s because the air is much thinner and less resistant at that altitude, and they need less fuel to overcome the drag. In space, a near total vacuum with very little matter, we can fly astronauts at speeds of nearly 25,000 mph.

This brings us to the hyperloop, which operates in a tube with a low pressure environment, allowing speeds of nearly 600 mph. In terms of sustainability, hyperloop is somewhat like an electric car that can fly in space but is restricted to where the tube is built.

Resilience is about how we adapt to shocks and stresses so we can absorb or quickly recover from those disruptions. Hyperloop has two key resilience attributes. First, it’s new, and because it’s built from scratch, it can be designed to adapt to the changes we know are coming. Much of our existing transportation infrastructure is old, and it’s often hard to retrofit older systems to be resilient to changes that were not known or anticipated when it was designed. The other resilient attribute of this new technology is that it provides additional capacity and another system. In a disaster, some systems will work and others will fail for reasons we can’t always predict. Disasters are often, by their very nature, unpredictable. Having more options is good for resilience. While it is possible that this system could be compromised like any other mode of transportation, more choices are better.

I don’t think governments and private organizations are going to invest in a system like the hyperloop solely because of its sustainability or resilience attributes. If you can deploy a safe and cost-effective ground-based transport system that travels at airline speeds, I think it’s safe to say you will have a market. However, as cities around the word race to adopt sustainability and resilience standards, it will be a major factor in how they consider their future infrastructure investments.