Uber-nomics: Here's what it would cost Uber to pay its drivers as employees

And if Uber drivers were salaried employees, they would be required to drive a larger number of hours per day than they currently do, increasing Uber's income-per-driver and decreasing the number of drivers that Uber would employ. According to http://time.com/3678507/uber-driver-questions/ 51% of drivers drive 15 or fewer hours per week. Only 19% of drivers drive 35+ hours/week. If Uber was forced to employ drivers as salaried employees, I'd expect their driver base to drop to 25-35% of what it is now (and their labor costs with it).

Trying to just take Uber's current numbers and tack on payroll taxes and insurance is ridiculous. These numbers are nonsense.

I'm confused by the time frame of the 4.1B.

Does it mean this year's operating cost assuming Uber's current state of operation (number of drivers, etc)? Does it assume backpay for drivers who are being reclassified?

These calculations are nonsense. If drivers became employees, 100% of the revenue would go to the company, and "mileage reimbursement" would be just part of the operating costs.