Japanese car maker Toyota has developed an app called Smart Key Box that lets people use smartphones to access and start up a car.

The app would only allow users that have previously signed up for the shared-use car to operate it, providing a more secure way of lending and renting cars, Toyota said in a statement on Monday.

For the pilot programme that will begin in San Francisco in January has invested in Getaround in October -- a peer-to-peer sharing service that allows private car owners to rent out their vehicles when they are not using them.

The device works with a cloud service where an individual can be given access to a specific car for a set time period, CNET reported.

According to Toyota, Smart Key Box "can be placed in a vehicle without modification," enabling engine start and door lock access.

The smartphone app, connecting to Toyota's cloud-based Mobility Services Platform, can also handle payments and loan scheduling.

"The platform has individual business functions like vehicle management systems and leasing programmes," Toyota said.