Now that you got the low down from the "Hater", it is a tough decision. His points are pretty much on except as I offer my observations below.
Yes, you can negotiate ... I have seen new promotees get 5% or more by negotiating. Never saw 10%.
There are very few internal (Drivers) candidates who are willing to take the leap.
The 5,000 for insurance is at your current age. If prescription drugs become an issue as you age, you can easily pay 5K - 10K additional per year. There is no cap limit on management prescriptions but it maxes at $300 per Rx filled.
A center manager total compensation is more like $120K including MIP award.
Supervisors and center manager do not get Stock Options. They get a bonus in the form of stock of which 50% is delayed for 5 years. If the stock goes up in price after 5 years, this can be a nice "bump" in bonus.
Make sure you will get a pension in management ( I don't think you do).
Consider how marketable your bachelor's degree is.
Liberal arts degree equals ZERO, finance and technical degrees equals a plus.
Obviously, as a driver, you are not utilizing the investment in that degree whether for money or for type of career.
The aging and "beast of burden" aspect of the driver job is definitely a consideration but the stress and BS in management takes it's toll as well.
The fact that you are in supervision with UPS will most likely give you better opportunity to get a comparable job outside UPS. Most UPS management people I know that have left (with a degree) make more than they did at UPS.
Drivers typically do not , losing half their pay typically. The UPS Package Driver is not a Skilled Trade as suggested by Hater above. It is an unskilled manual labor job done at a very fast pace to justify the high compensation. If you leave UPS as a driver, your chance of getting job making caomparable is very slim.
Maybe in California or NYC but not in most of America.
2004 was dire period to be moving into management at UPS.
Opportunities will be increasing over the next 5 - 10 years.
Good luck with your choice.