On the other hand it is more fair for the people using the new bridge to pay for it than for previous generations to pay for the old bridge and then keep paying for the new one which they will never see.
I consider infrastructure like bridges to be fundamental constructs of society, something we should build to promote the general welfare. I willingly pay for infrastructure today that will get more use by my children than I will ever see, and I think that is fair. My parents contributed to much of the infrastructure I am using.
There is a huge difference in being taxed to create and maintain infrastructure that you and your children will both use, and being taxed to fund future hypothetical infrastructure that you will never use.
I don't like that we as a country put off the costs of maintenance as long as possible thus creating debt for future generations, but asking the current generation to create a savings fund to pay the future generation's (non emergency) expenses is a bridge too far.
And that’s how we ended up with the selfish Boomer meme. Previous generations set them up for success. Rather than paying it forward, they kept those funds along with their own economic growth and left the rest of us in the lurch.