If I leave before about 5:45 AM, I can ride the Jamaicaway and am passed by at most about 10 cars in a two-mile stretch. The VFW Parkway is OK even later because it has a shoulder, and the cars usually pass in clusters. Route 1 proper (Providence Highway), in Dedham, is wide with a wide shoulder, and lightly traveled even as late as about 6:30 AM. I always ride 1A from Dedham into Norwood.

Most of my riding in Metrowest is on weekends, so I'm sure you have a much different view on weekdays.