Susie Wolff has been promoted to official test driver for Williams for the 2015 Formula One season, increasing her chances of becoming the first female racer on the grid since 1976.

Wolff will build on her three seasons as the team's development driver by taking part in the first two practice sessions at races still to be determined, as well as two test days. She will also conduct extensive simulator testing to help with the development of Williams' new cars.

If Valtteri Bottas or Felipe Massa were to miss a race next season, the 31-year-old Wolff would be first to step into the seat.

Italian driver Lella Lombardi was the last woman to race in F1.

Wolff drove in practice ahead of races in Britain and Germany this year.