In a nutshell: A sleek new train is breaking ground in eco-friendly transportation. At first glance, it may look like any other modern metro, but China's Cetrovo 1.0 Carbon Star Express is the world's first passenger train made primarily from lightweight carbon fiber. It has officially started carrying commuters this month. Unlike typical steel subway cars, the Cetrovo's body and frames are constructed from ultra-strong, ultra-light carbon fiber composites the same material that supercar manufacturers like Ferrari, Lamborghini, and McLaren employ to reduce weight while maintaining structural rigidity. The result is improved acceleration, handling, and fuel efficiency.This ultralight construction has some of those same benefits, particularly fuel efficiency thanks to reduced weight. The Cetrovo is around 11 percent lighter than others in its class, translating to about seven percent less energy consumption. Chinese media outlet People's Daily Online reports that those savings equate to around 130 tons of CO2 emissions, equal to the air-cleaning benefits of planting 100 acres of trees.Cetrovo's carbon fiber construction offers benefits beyond being more environmentally friendly. For one, the material brings lower operation and maintenance costs for the train throughout its life cycle. Additionally, since it's five times stronger than steel pound-for-pound while weighing just 25 percent as much the cars should be more rigid and impact-resistant than steel rail cars. Riders can also expect a smoother, quieter journey thanks to reduced vibration.It's been a long road bringing this green transportation machine to life. State-owned CRRC Qingdao Sifang, the company behind the Carbon Star Express, began research and development in 2021. The resulting prototypes underwent years of intensive testing and evaluation.During trials last year, the train demonstrated its potential by cruising at over 87 mph, which blows past the 50 mph average of current Chinese metro systems. It also demonstrated automated operation and high-tech safety features like anti-collision warning and obstacle detection.The Express is now running autonomously on a 37-mile route with 41 stations called "Line 1" and will serve as the Cetrovo's initial proving grounds in Qingdao. If this groundbreaking train is successful, we could see carbon composites displacing steel as the material of choice for future mass transit projects across China and other nations.