You know about the proposed high-speed “bullet” train that would connect Dallas and Houston, and you might have heard of the proposed transportation-in-a-tube concept that would link Dallas, Austin, Houston, San Antonio, and Laredo.

Now, another possible alternative to planes, Amtrak trains, and automobiles has chugged into the picture.

Virgin Trains USA, a transportation startup that plans to trade its shares on the Nasdaq stock exchange, is exploring two high-speed routes in Texas — one between Dallas and Houston, and the other tying together Austin, Houston, and San Antonio. All four of the cities are plagued by ever-increasing traffic tie-ups.

There’s no word yet on when these routes might take shape. At this point, they’re merely ideas, and ahead of the company going public, officials at Virgin Trains are staying mum.

In all, Virgin Trains has outlined seven potential routes in the U.S. beyond what it already has on the drawing board.

“Our goal is to build railroad systems in North America that connect major metropolitan areas with significant traffic and congestion,” the company says in a filing with the U.S. Securities and Exchange Commission.

Virgin Trains aims to tie together heavily populated cities separated by 200- to 300-mile distances that are “too long to drive, too short to fly.” It wants to run the trains along existing transportation corridors — rail, highway or a combination of the two — “to cost-effectively build our systems, as opposed to developing entirely new corridors at potentially significantly higher costs.”

If the Virgin name sounds familiar, it should. British billionaire Sir Richard Branson’s Virgin Group is a minority investor in Virgin Trains, which already operates a South Florida route between Miami and West Palm Beach. West Palm Beach-to-Orlando and Orlando-to-Tampa routes also are in the works in Florida, in addition to a Los Angeles-to-Las Vegas route. Virgin’s other transportation investments include airlines and space travel.

Jim Mathews, president and CEO of the Rail Passengers Association, says he’s on board with the Branson-backed Virgin Trains venture — not as an “anti-Amtrak” move but as an advancement in U.S. passenger rail travel.

“Speaking from the experience of someone who spent almost his entire career watching Sir Richard innovate, invest, and take risks, I firmly believe this could be a real shot in the arm for passenger rail in the United States,” Mathews writes on the association’s website. “Like all entrepreneurs, Sir Richard isn’t afraid to fail, and he has made a few bad bets in the past. But he’s also made some very good ones, and has transformed not just travel but philosophies wherever he has gone.”