A new highway is to be constructed. Design A calls for a concrete pavement costing $90 per foot with a 20-year life; four paved ditches costing $4 per foot each; and three box culverts every mile, each costing $10,000 and having a 20-year life. Annual maintenance will cost $1,700 per mile; the culverts must be cleaned every five years at a cost of $450 each per mile. Design B calls for a bituminous pavement costing $40 per foot with a 10-year life; two sodded ditches costing $1.45 per foot each; and three pipe culverts every mile, each costing $2,200 and having a 10-year life. The replacement culverts will cost $2,400 each. Annual maintenance will cost $2,800 per mile; the culverts must be cleaned yearly at a cost of $230 each per mile; and the annual ditch maintenance will cost $1.40 per foot per ditch. Compare the two designs on the basis of equivalent worth per mile for a 20-year period. Find the most economical design on the basis of AW and PW if the MARR is 10% per year. Click the icon to view the interest and annuity table for discrete compounding when the MARR is 10% per year. The AW value for Design A is $ - 71200 /mi. (Round to the nearest hundreds.) The PW value for Design A is $ -606000 /mi. (Round to the nearest hundreds.) The AW value for Design B is (Round to the nearest hundreds.)