The metro is coming to Loudon County, Virginia. Eventually.

The Silver Line expansion that opens this summer will only go as far as Reston, but by 2018 it’ll be in Loudon, one of the nation’s fastest-growing — and wealthiest — counties.

As the county’s population continues to grow — especially among communities of color — will its density hit 800 people per square mile, which is the threshold at which places magically turn from Republican to Democrat? And if it does, will it turn Virginia from purple to blue? And with such an important swing state shifting solidly to one camp, does that change the national political balance? And what is it with the number 800 anyway?

We try to figure it all out on this week’s Talking Headways. Plus, Stephen Miller, my colleague from Streetsblog New York, joins us to talk about what is — and what isn’t — moving forward as part of the city’s Vision Zero plan.

And: Detroit is tearing down more than 20 percent of its housing stock to reduce blight and still splurges on roads. Is that the way to revitalize a city? The comments section awaits you.

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