Google’s self-driving car Chief Technical Officer (CTO) Chris Urmson has left the company after serving seven and half years with the team.

Chris Urmson was a research scientist at the Carnegie Mellon University, before he joined Google in 2009.

Back then, the self driving car was a secret project of the search major and Urmson took over as team lead, after Sebastian Thrun , the founder of Google X lab, quit in 2013.

Google recently appointed John Krafick from Hyundai America as the chief of the self driving car project. According to New York Times, the search engine giant has plans to float the self driving car project as a separate entity, a subsidiary under the Alphabet group of companies.

There are reports that Google X is under pressure from its parent company to demonstrate financial gains from its projects.

The self driving car project is a promising new technology, but it could take several years before a commercial version of the project could be released to the general public.

The New York Times also noted that Urmson was unhappy about the turn of events and had reportedly had  differences with Krafick. These could have forced Urmon to leave the organisation.

When Google began the self driving car project, it was perceived only as an idea or a theoretical concept, which could take many years to become reality. But, Urmson had been a vital force in developing the project.  At present, the project is at a crucial juncture where it could soon become a reality.

In his blogpost Chris Urmson said: “Now, 1.8 million miles of autonomous driving later, I’ve decided the time is right to step down and find my next adventure. Today will be my last day on the project as CTO.

“After leading our cars through the human equivalent of 150 years of driving and helping our project make the leap from pure research to developing a product that we hope someday anyone will be able to use, I am ready for a fresh challenge.”

He also said: “If I can find another project that turns into an obsession and becomes something more, I will consider myself twice lucky.”

Apart from Chris Urmson’s resignation, two other engineers are also quitting from Google including Dave Ferguson and Jiajun Zhu. Jiajun Zhu is the principal software engineer and Dave Ferguson is also one of the software leads.