Dumfries is south of Lorton, but I've never stayed there since I live so close. I'd say it's a safe area, but it's farther away that Woodbridge. Woodbridge is less than 10 miles, more like 4-5 miles. There's also a town called Occoquan close to Woodbridge that is right on the river. Do a Google search for both and see what's available. I've never really paid attention to the hotels there since we tend to exit farther south onto I-95 than the Woodbridge area, but I can tell you from the times I've been through there, there's plenty of places to eat, shop, etc in Woodbridge and I know there are several hotel chains, because I did a quick Google (Comfort Inn, Wytestone Suites, Fairfield, Hampton Inn). DC traffic is a nightmare if you hit it at rush hour (like any other city). It's not bad on the weekends especially if you come through early and in the summer it's a route used to get to the VA/NC/SC beaches. I love how everyone thinks traffic here is so horrible. I've been in many cities and I've seen traffic just as bad and worse, (Atlanta, LA, New York, Dallas). It's perception and planning.