I have a REAL situation. If that user name and problem title truly indicates how you feel about yourself, you will fail miserably in your mathematical tasks.
Unfortunately, this problem can be solved only in your head. It may not require much by way of math. How do you feel about your business? How did you determine "traffic density"? What sort of measure might constitute a Driver Rating? Is Package Count really a good measure of driver effectiveness? Have you considered delivery difficulty? Maybe one just has to drop off 10 packages at an apartment building and the other has to walk down 500 ft driveways with each package.
Simple...
1000 * 20 = 20,000
500 * 64 = 32,000
...but is it meaningful AT ALL? Is Driver #2 REALLY 32,000/20,000 - 1 = 60% better than Driver #1?! If this were so, surely you would already have noticed - without doing any arithmetic.
Have them switch and do each others' routes for a few months. See how it goes.
Seriously, there is no simple answer even after you decide how you wish to measure it. This is only just barely a math problem. One thing we learn in all business comparisons is that the participants will figure out the measuring system and exploit it in any way that is to their advantage. Faster isn't always better. More isn't always better. Example: During an orientation for a new job, I was offered 2 pieces of information:
1) We take 20,000 calls a week.
2) Our goal is 95% happy customers.
Those might sound good, but MY first response was, "So, we're okay with 1,000 unhappy customers a week?!" The presenter laughed and smiled at me: "We were hoping someone would spot that problem."
