The long-discussed plan to link O’Hare International Airport and downtown Chicago via high-speed rail has found a surprising West Coast ally—billionaire entrepreneur Elon Musk. Though he is known for companies such as PayPal, Tesla, and SpaceX, Mr. Musk’s newest pet project—a venture known as the Boring Company—has city officials most intrigued. While previously discussed schemes to connect O’Hare to the Loop would see express trains share congested right-of-ways with slower Metra or CTA traffic, the Boring Company is offering the far more ambitious solution of digging a dedicated tunnel.

Founded just last year, Musk’s firm claims it can dramatically reduce construction costs by using more affordable equipment and drilling more narrow—and therefore cheaper—shafts. Instead of utilizing standard-sized trains, the innovative solution would deploy a higher number of much smaller passenger cars that would ride on electromagnetic “sleds” at speeds of up to 125 mph. Chicago Deputy Mayor Steve Koch even flew out to LA last week for a face-to-face with Musk regarding the still experimental technology and returned “impressed,” reported Greg Hinz of Crain’s.

[Warning, this may cause motion sickness or seizures] This is a test run of our electric sled that would transport cars at 125 mph (200 km/h) through the tunnels, automatically switching from one tunnel to the next. Would mean Westwood to LAX in 5 mins. A post shared by Elon Musk (@elonmusk) on May 12, 2017 at 5:48am PDT

City Hall’s desire for a high-speed link between Chicago’s downtown and its international airport is hardly new. Former Mayor Richard M. Daley first envisioned such an express service to ORD back in the early 1990s. Mayor Emanuel then resurrected the idea back in 2011 and just last year tapped an engineering firm to explore potential solutions. With Elon Musk’s reported interest, the answer looks exciting—albeit risky and technologically unproven.

The City of Chicago plans to formally seek bidders for the O'Hare link later this year. Even with Musk’s fresh approach to low-cost tunneling, the project is still expected to cost billions and would require major support from private investors.