Anyone who’s spent time traveling in Europe or Asia has probably come home wondering: Why don’t we have a high-speed train system like that?

Europe’s high-speed trains travel at about 186 miles per hour and one of China’s high-speed lines tops out at 267 miles per hour. The average speed of a passenger train in the U.S.? A comparatively slow 50 miles per hour.

The U.S. High Speed Rail Association (USHSR) has put together a proposal for building out a network of high-speed rails across the U.S. The plan would include building out the rails around large, densely populated areas first and then connecting those regional networks to form one big national system. The result would be the ability to cross the country from East to West Coast in 20 hours. That journey on today’s rails would take a very slow 80 hours—that’s four time as long.

The U.S. does have one high-speed train, Amtrak’s Acela express service between Boston and Washington D.C., which has a maximum speed of 150 miles per hour. In reality, however, the service only averages speeds of around 70 miles per hour. The reason? As the Boston Globe explains, “aging infrastructure, number of stops, and sharing the track with freight trains and other commuter rails cause significant delays.” New, updated tracks are a key part of the USHSR’s vision.

Business Insider put together a handy visual of the association’s proposal. Check it out: