Page 62 - SAPEM-Chapter-10-2nd-edition-2014

South African Pavement Engineering Manual
Chapter 10: Pavement Design

DETERMINE GENERAL DESIGN INPUT
PARAMETERS

Time of traffic survey or date of published/known data
Section 4.5, Figures 22, 23 & 25
Date of opening of the facility

DETERMINE THE FOUR BASIC INPUT VARIABLES
Daily heavy vehicle volume for the base year Section 4.3

Heavy vehicle volume growth rate Section 4.3, Table 17, Equation 12
E80/HV for the base year Section 4.4.3, Table 18

E80/HV growth rate Section 4.4.3, Table 18, Equation 13

CALCULATE THE ADE AT THE TIME OF THE Section 4.3, 4.3.1, Equation 4
TRAFFIC SURVEY

Heavy Vehicle Volume
E80/HV

Adjust for lane distribution (if necessary) Section 4.4.1, Table 13

ADJUST ADE TO AADE Section 4.4, Equation 5, 7, 8, 10 & 11

Weekend/weekday variations Section 4.4.2.1, Table 14, Equation 5
Seasonal variation Section 4.4.2.3, Table 15, Equation 10 &11

Exceptional periods Section 4.4.2.2, Table 15, Equation 7 & 8

PROJECT AADE FROM DATES OF TRAFFIC Section 4.5, Equation 14
SURVEY TO OPENING

AADE Growth Rate Section 4.4.3, Table 17, Equation 13
Heavy Vehicle Volume

E80/HV growth rate

CALCULATE EQUIVALENT DESIGN TRAFFIC Section 4.5, Equation 15

Base year AADE
AADE Growth Rate
Structural Design Period

Figure 27. Calculation of Design Traffic

Section 4: Design Traffic Estimation
Page 51