I think it'll be more like 1hr 15 but, regardless, that's just the train portion...

The thing that everyone forgets is that, because this is a surbuban station, basically everyone in Ashburn will have to get in a car (maybe a bus), and drive to Ashburn Station. The amount of time it takes to drive to a train station, drive around finding a parking space, walk through the parking lot, take an elevator/stairs to the right level, possibly even cross over a walkway, to even get into the train station, adds a ton of additional time on top of that 1hr 15min.

Something people also tend to forget is that if people are already in their car driving to a metro stop, many will realize that they can save a lot of time by driving to a Metro drop closer to D.C.

I know this from personal experience back when I lived in Sterling. I was 20 minutes from Wiehle and was excited to use it to go into DC. I ended up using it once in 3 years because it actually took forever.

For weekenders, it's no contest. It's easy to find $10 parking in D.C. and they can cut their travel time in half by driving instead of Metro-ing.

Oh, and don't forget parking $4.50/day or so.