TORONTO (Reuters) - Canada has tapped Google parent Alphabet Inc (>> Alphabet) to help plan a mixed-use development along Toronto's Lake Ontario waterfront using cutting-edge digital technologies and urban design.

Alphabet's Sidewalk Labs unit, which is developing new technologies for use in "smart cities," said it would invest $50 million in the initial planning and testing phase of the project, which will create a new neighborhood called Quayside.

"For the foreseeable future this will be the primary focus of what we do," Dan Doctoroff, the chief executive of Sidewalk Labs, said in an interview.

One of the first projects Sidewalk Labs will take on is a sensor-based technology to manage crowds on a nearby street often filled with a potent mix of pedestrians, cyclists and motorized traffic, which Doctoroff said could be tested as early as the first quarter of 2018.

He said the company was also looking to integrate self-driving technology into the project over the longer term.

Assuming initial success, Sidewalk Labs could expand its partnership with Waterfront Toronto, the public agency funded by federal, provincial and city governments with a mandate to develop a much larger area nearby of industrial wasteland.

Doctoroff said the company had looked at more than 50 metropolitan areas in North America and sites in western Europe and Australia before settling on Toronto as the prime location for its future city test bed.

Google said it would move its Canadian headquarters and some 300 employees to the district once it is completed. Prime Minister Justin Trudeau, who announced the partnership with Google, said he hoped that Quayside would become "a thriving hub for innovation and a community for tens of thousands of people to live, work and play."

It is Sidewalk Labs' most ambitious project to date, which the company expects will house 5,000 people and host another 5,000 workers within three to four years.

The Google unit has previously worked with Qualcomm Inc (>> Qualcomm) and Civiq Smartscapes to retrofit New York City phone booths into digital billboards that serve as WiFi hotspots.

Intersection, the Sidewalk Labs subsidiary behind the effort, recently launched similar kiosks in London. Another division, Flow, has held talks with cities such as Columbus, Ohio, about providing software to evaluate transit programs.

Doctoroff said he expects the project to lower the cost of living, including by reducing commutes, and for it to be the world's first urban development to reduce a city's carbon footprint.

(Reporting by Alastair Sharp in Toronto, additional reporting by Andrea Hopkins in Ottawa and Paresh Dave in San Francisco; Editing by Steve Orlofsky and Cynthia Osterman)

By Alastair Sharp

Stocks treated in this article : Qualcomm, Alphabet