A new highway is to be constructed.

Design A calls for a concrete pavement costing $85 per foot with a 16-year life;three paved ditches costing $4 per foot each; and four box culverts every mile, each costing $8,000 and having a 16-year life. Annual maintenance will cost $11,800 per mile; the culverts must be cleaned every four years at a cost of $300 each per mile.

Design B calls for a bituminous pavement costing $40 per foot with a 8-year life; two sodded ditches costing $1.40 per foot each; and two pipe culverts every mile, each costing $2,200 and having a 8-year life. The replacement culverts will cost $2,400 each. Annual maintenance will cost $2,900 per mile; the culverts must be cleaned yearly at a cost of $230 each per mile; and the annual ditch maintenance will cost $1.45 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 6% per year.