Sometimes news hits you over the head.

That's the case with an e-mail last week telling us AJC employees that we're moving around the corner to the Cox Enterprises headquarters. It turns out the ugly building we currently rent will be levelled to create a development whose working title is Megapolis Behind The Mall.

The preliminary plan would create a 42-acre-complex with 3,000 rental and condo units. It would cram a population more than twice that of Avondale Estates into a few blocks of live/work/play hipness. High Street, its official name, could include 400,000 square feet of retail and restaurants, a million square feet of office space, 750 hotel rooms, promenades, parks and plazas. It would, according to its Boston developers, “transform Atlanta’s Perimeter Center area and become its urban heart.”

And there will be parking, because although the mini-city will be across the street from the Dunwoody MARTA rail stop, Atlantans mostly prefer to stew in traffic. So there would be 8,500 parking spots.

This all would be kitty-corner from a 17-acre State Farm campus that ties into the MARTA station. State Farm reportedly paid $8 million per acre at the corner, so the company must amortize the cost by going vertical. The development's first phase has a 585,000-square-foot, 20-story tower going up as I type. Once again, even though the building is being virtually infused into the MARTA stop, people will still drive. Enough to fill seven stories of parking deck.

But don’t worry; all this will have no impact on traffic, because traffic engineers will time the stop lights, re-stripe the pavement and make sure bicyclists feel welcome.

Actually, I’m kidding. The corner of Hammond Drive and Perimeter Center Parkway will resemble the traffic snarl in the opening credits of “The Walking Dead.” Half the time, it already does.

Dunwoody Mayor Mike Davis said the city is working with state DOT planners and engineers to mitigate potential mayhem in the area, which also feels the crush of neighboring Sandy Springs. Developers there are also putting up buildings as fast as carpenters can hammer.

Traffic “is going to get denser before we figure it out. It will be interesting to see how we sort that all out,” said Davis, a master of understatement.

Dunwoody officials inherited Megapolis from DeKalb County, which approved the zoning before the city was incorporated in 2008. In fact, it would be fair to say that former county CEO Vernon Jones, a large reason why Dunwoody was created in the first place, is enjoying this a good bit.

The city was created as a leafy suburb with 4-bedroom ranches walking distance from community swimming pools. But, Davis said, “the millennials don’t want that. They want to go downstairs and have their pick of six restaurants.”

Millennials are the new generation that developers are still trying to figure out. Millennials wear porkpie hats and make us Boomers look old, stodgy and avaricious because they don’t want to drive or buy homes. And they love craft breweries and tapas.

Megapolis is the latest wrinkle in the tension in Dunwoody between those residing on the suburban lanes, who elected Davis, and the burgeoning commercial interests who pay the city’s freight.

“It’s a real rub to some old-time Dunwoody residents who still see it as a cul-de-sac community,” said Tom Taylor, a Boomer who is a Republican state rep and one of Dunwoody’s chief incorporators. But things are changing. The 2010 Census revealed that more than half the city’s 22,000 structures are multi-unit and the city is almost half renters.

The mayor and council members must toe a fine line between accommodating growth and keeping true to the folks who take time from watering their lawns to vote in local elections.

“The business community loves (Davis); he’s attracted a lot of business,” said Taylor. “But that doesn’t guarantee him re-election. They don’t vote here.”

Fran Millar, the Republican State senator from Dunwoody, said huge developments always bring the same two issues: Crowded classrooms and clogged roads. Dunwoody has become popular with many renters because of the quality public schools in the area, a continual undercurrent that brings together issues of education, race and class.

“Every time there’s one of these coming along, the developers say there will be one-third of a child (per unit). But I’ve yet to meet one-third of a child,” Millar said. “But that, unfortunately, gets neglected, the impact on the schools.”

Millar said Dunwoody residents have their own routes to avoid much of the traffic mess near I-285. But as Atlantans have seen recently, a highway fatality or a camera with duct tape will shut the metro area down. Alternative routes, especially of the east-west variety, are at a premium.

The $1 billion interchange improvement project coming at I-285 and Ga. 400 might ease some of the gridlock, but, then again, maybe not, because it doesn't address the feeder roads that easily clog. In fact, it may even make them worse.

One obvious east-west alternative route in the area is also “a line in the sand” when it comes to the Dunwoody long-timers, Millar said.

“We are not widening Mount Vernon Road,” said Millar. “If you do that, you’ll bring more traffic.”

But, Millar, who often comes across as cranky, eases up a bit when talking about the inevitability of change.

“Whether I like it or not,” he said, “this live/work/play thing is going to happen.”

And one day, I assume we’ll discover Millar with a porkpie hat, downing some tapas in a Perimeter brew pub.