Experience shows that even if we wanted to build an infrastructure to allow this, we would never be able to keep up. Va. has developed in a low-density pattern of sprawl, both residentially and commercially.
People do use mass-transit to travel to Washington and even Arlington.
If you work in the Tyson's Corner area, though, transit options do not offer enough of an advantage, so people continue to drive despite the horrific traffic. I would like to people to feel good about alternative transportation. But I think the only reason they'll likely feel this way is because its so much better than driving. That means less roads, less parking, and a whole lot more transit options. If we stick to this, development will tend toward higher-density options with good transit access.