The oldest example in the U.S. dots the East Coast from Boston to Washington. There’s one in Texas made up of Dallas, Houston and San Antonio.

It’s called a megalopolis and it’s a larger, economically diverse region anchored by urban centers and connected by well maintained highways or high-speed rail.

Nevada city planners see the potential for a megalopolis in the Southwest consisting of Los Angeles, Phoenix and Las Vegas. Although Los Angeles and Phoenix would be the bigger fish in that mega-pond, according to Robert Lang of the Brookings Institute, Las Vegas could play a significant role.

“We have a lot of tourists from Southern California,” says Lang. “A third of our flights that leave McCarran actually go to Southern California, and a lot of the trade that comes through the port of Los Angeles flows through our city as well.”

Mike Majewski, a Southern Nevada economist and city planner, says that the secret of getting people to embrace the megalopolis concept lies in changing their mindset.

“Nobody would think twice about when they decide to go shopping, or for entertainment, or for eating, to cross a border, to cross a street from north Las Vegas to Las Vegas, or from Las Vegas to the county,” says Majewski. “We need to expand that kind of thinking to include state borders as well.”

There are obstacles to connecting cities beyond changing minds and building infrastructure. Lang says the reason Interstate 15 is in bad repair is because of special interests who won't embrace regionalism.

“Indian gaming has been working the California legislation not to improve it, not to widen it, because they’re afraid they’ll lose business to Las Vegas, quite frankly,” says Lang. “What’s interesting about high-speed rail is that it gets around that problem.”

Majewski says the key to forging a successful regional economy lies in leadership, and not from bureaucrats.

“You need someone in the private sector,” says Majewski. “You need someone to take the bull by the horns and say this is what we’re going to be.”