what would be better is 30-40 mph rds if you can find them. bike sharrows a bonus
avoid roads like this
speed limit here is 30mph, I was well over that & still got passed at a high speed
use mirrors & if you hear a big motor coming from behind & oncoming traffic on the other side, take a look in the mirror. don't be afraid to pull over & let whatever it is pass you. up here in the Boston area, what kills urban bikers is trucks making turns at complicated intersections, at slow speeds. don't get squished