Remember that Bike Route 1 is not necessarily the same thing as the regular Route 1. I live near Bike Route 1 in Midlothian, south of Richmond, and it's nowhere near the regular Route 1. VA DOT's Bicycling in Virginia map, in fact, suggests that very little of Bike Route 1 and regular Route 1 overlap between Richmond and northern Virginia. Here's the link to order the map:

http://www.virginiadot.org/bikemap/

I'd be interested to hear from anyone who has taken Bike Route 1 between Richmond and northern Virginia--I've been thinking about doing the trip, but I've never been north of the James River on it, and I'd be interested to know what things look like through Richmond and beyond. The sections through Chesterfield county, for what it's worth, seem well selected. It's well marked as a bike route, and it does a good job of staying away from heavy traffic.