Question

Q1: The predicted traffic mix of a proposed four-lane urban freeway: Passenger cars = 69% • Single-unit trucks o 2-axle, 5000 lb/axle = 20% o 2-axle, 9000 lb/axle = 5% o 3-axle or more 23,000 lb/axle = 4% Tractor semitrailers and combinations: 3-axle 20,000 lb/axle = 2% The projected AADT during the first year of operation is 3500 (both directions). If the traffic growth rate is estimated at 4% and the design life = 20 years, determine the total equivalent single axle load (ESAL). Assume the design lane factor fa is 0.42, pt = 2.5, and SN = 3.

Answer 1

Criven data: growth rate MDT (Armud Avg daily hoa ftic) 1 - 350 (Curd) -4% design life n-goyers design lave factor LDF = 0.42 = 3 P1-2.5 (VDF) SN Total Equivalent single axle load is given by the formula (044)*-"] LDF LDEX UDEXON No Ź 365A "r 100 A - Annual ang daily traffic 8-growth rate n-design life LDF, VDF fsN - design factor expression but the value in above 20 X 0.42X 2.583 100 No = 365 X 3500 (4100) INS 1277500 y 1.191 X 0.42X9.5X3 0.04 Ns = 1198 18321-9 standard anle 08 Ns = 119.82 MSA