Australia will also have two berths in the individual time trial, where Rohan Dennis is the defending world champion.
Spratt, who won bronze at the world road championships in September, is among the favourites for the 137km women’s road race.
The powerful Dutch women’s team will also have four berths, as will Germany, Italy and the United States.
Australia will have two women’s time trial starts, but Kat Garfoot’s retirement means the event is less of a focus.
The men’s 44.2km time trial and women’s 22.1km event will be held on July 29.