We tried that method as well. It goes well if everyone agrees and values their job. All it takes is to have a rough week and they don't value their job as much. The driver decides to move, call 1-900 numbers until the plan shuts them down, leaves, and you have a very large phone bill that you cannot recover from the driver.We did have that happen - I actually called the labor board to find out the legal way of doing this - they said a blanket form is no good - we had to get them to sign one every month. we had some pretty good guys. You can take whatever out of their pay as long as you have a signed paper for each deductions other then normal payroll.
In the end all you can do is sue the driver personally and hope he pays.