I don't do anything but time trials so I can't tell you much about training. For speed, search for results of the races in your area. They are posted a great deal of the time. Do the math. You'll be able to figure out the average speed. Then, remember that in a road race they are in pacelines so the average speed is high.

One other thing, good road racers can put in bursts of speed to catch or stay with a breakaway. A skill a lot of us don't work on.