HOW the work is done is chosen by the driver. They are free to take a different route

The employer's business is connecting cars to riders with software. The driver's usual job is HR, and he uses the lyft service to make extra cash on his way home.

The last point is not something that determines a contractor. What you choose to do for money does not have to be a trade. It can be anything.

There are no working hours. You don't get paid by lyft for hours you 'work.' You get paid for engagements you pick -the rides. Getting paid per project, not for time you put in makes you a contractor for that gig.