The notion of a tunnel system allowing for high-speed travel between Washington and Baltimore is still a theoretical, pie-in-the-sky, maybe-it-will-happen-maybe-not idea, but if it happens, we have some idea of the route it may take.

The Boring Company released some details of its proposed East Coast “Loop”, featuring two twin tunnels that will allow for trips between the two cities in about 15 minutes. The system would allow for other trips in between. (For example, a DC-to-Greenbelt trip could take 5 minutes.)

Current plans call for a 35-mile alignment along the Baltimore-Washington Parkway from Paca Street in Baltimore to New York Avenue in D.C. The tunnels would be at least 30 feet underground. The entire project would be privately funded, though the Boring Company said it is working with a variety of government agencies on plans.

“This would serve as the central artery for a potential future transportation network which would hopefully be extended to New York,” the company said.

Riders of the Loop system would sit in “electric skates” traveling 125-150 miles per hour and seat between eight and 16 people. The Loop is different than the Hyperloop, which promises to travel people in similar fashion up to 600 miles per hour. But, the systems are designed to be compatible.

“A Hyperloop trip from D.C. to New York would be less than 30 minutes, so we are hopeful that this tunnel could eventually be part of that trip,” the Boring Company said.

This system is also separate from the proposed MagLev rail system that would connect DC and Baltimore along a similar alignment.