Utility doesn't aggregate. Neither human lives. You don't use 4, you have to use 1+1+1+1. If you aggregate human lives, you get diminishing marginal value for huma life/ Goverment does it. Millitary does it. You send a squad to suicide missoin to save the division. A la guerre com ala guerre. So I agree with Jadagul. Preference is a tricky subject , in which, there is always marginal utility.
But since you used economic term of utility here is a simple economic question upon aggregate utility:
You are the Goverment. You need to raise 1 Million $ for, let say, the new interchange.
You can get the money by 9 ways: increase taxation of 100M people by 0.01$, 10M people by 0.10$ .... 1 man by 1 million. Can you draw a histogram of disutility for the 9 cases?