Using the current specifications a new road will cost $$1\mathrm{.}5$M initially, it will need $$120$K in annual maintenance, and it will need to be resurfaced every $10$ years for $$1\mathrm{.}1$M$.$ A proposed new specification is expected to be more resistant to wear. The initial cost will be $$2\mathrm{.}1$M$,$ it will need $$90$K in annual maintenance, and it will need to resurfaced every $15$ years for $$1\mathrm{.}3$M$.$ At the highway department$$s $6\%$ interest rate,$$how much better is the PW for the best alternative?