In my opinion, the $40/hr could be per patient/visit on a weekend schedule, or if the person was doing overtime.
The Caritas VNA that I talked to said that the staff gets reimbursed for every mile they drive. It's a few cents per mile and the RN told me that it's more than enough to cover the gas used per mile, etc.
The VNA's RNs also said they make less here than if they were to work in a hospital. [but of course, their schedules would not be so flexible so they preferred VNA.] So, that $40/hr might not be a normal everyday thing. However, I do not work at a VNA so I don't know the exact numbers! :)