Sometimes, attacks are nothing more than maintaining your speed when the others slow down to rest. Paceline is a very important tool in road racing where groups will often spend miles grinding away at each other. Blocking becomes very subtle and calculated. Most sprints tend to be in small groups and, often, uphill. A good road race is almost a religious experience.
Most people think that endurance is the most important tool for road racing.
Nope, it is still speed. California racing is very different between Northern California and Southern California. When my farm program's first set of riders made it to cat 3, I sent them to Northern California for their first road race against real roadies. They were very concerned about the stamina of the Nor Cal roadies since they had all been riding nothing but criteriums. I told them that most roadies tend to be plodders and don't have the top end speed of crit riders.