Williams test driver Susie Wolff has announced she will retire from motor racing at the end of 2015.
Wolff became the first woman to drive in Formula One for 20 years when she participated for Williams in a practice session for last year's British Grand Prix. She had four subsequent practice sessions for Williams since then and was promoted from development driver to a test drive.
Her ambitions to land a full-time F1 drive appeared limited, especially after Williams signed Adrian Sutil as injury cover for Valtteri Bottas earlier this year, and Wolff says this eventually prompted her decision.
"It was a decision I made at the end of the summer," Wolff told the BBC. There was very little opportunity to carry on in Formula One. My goal was to get on to the starting grid and that didn't look achievable. So I had to call it a day."
"I always said that as soon as I couldn't get any further I would stop and that time has come."
Wolff will make one further appearance as a racing driver at the Race of Champions at London's Olympic Stadium, where she is set to race for Scotland alongside David Coulthard.
Williams deputy team principal Claire Williams said: "It has been a pleasure to work with Susie over the years and see her develop as a driver within the team. Her feedback and knowledge of the car has been an important part of our recent development and we will be sorry to see her go"
"We want to thank her for all her efforts and wish her the very best for her future endeavours. We will of course be supporting both Susie and Felipe [Massa] at the Race of Champions, and hope Susie has a great weekend to mark the last time we see her race."