A new highway is to be constructed. Design A calls for a concrete pavement costing ?$75 per foot with a 16?-year ?life; three paved ditches costing ?$5 per foot? each; and four box culverts every? mile, each costing ?$8,000 and having a 16?-year life. Annual maintenance will cost ?$1,900 per? mile; the culverts must be cleaned every four years at a cost of $500 each per mile.
Design B calls for a bituminous pavement costing ?$30 per foot with a 8-year ?life; two sodded ditches costing ?$1.65 per foot?each; and two pipe culverts every? mile, each costing $2,150 and having a 8-year life. The replacement culverts will cost ?$2,450 each. Annual maintenance will cost ?$2,800 per? mile; the culverts must be cleaned yearly at a cost of ?$220 each per? mile; and the annual ditch maintenance will cost $1.60 per foot per ditch. Compare the two designs on the basis of equivalent worth per mile for a 16?-year period. Find the most economical design on the basis of AW and PW if the MARR is 8?% per year.
The AW value for Design A is ?$_________/mi ?(Round to the nearest? hundreds.)
The PW value for Design A is ?$_________?/mi. ?(Round to the nearest? hundreds.)
The AW value for Design B is ?$_________?/mi.?(Round to the nearest? hundreds.)
The PW value for Design B is ?$_________?/mi. ?(Round to the nearest? hundreds.)
The most economical design on the basis of AW and PW is ___________