In this formula, W is the width of the highway; hl
and hr, are the vertical distances of the left and right
slope stakes above grade; dl and dr are the center-line
distances of the left and right slope stakes; and c is the
depth of the center-line cut or fill. Applying the
formula for station 305 + 00 (fig. 10-4), you get the
A = (40/4)(8.2+ 12.3)+ (9.3/2)(29.8+ 35.3)= 507.71
AREA OF FIVE-LEVEL OR IRREGULAR
SECTION. Figures 10-6 and 10-7 are the field notes
and plotted cross sections for two irregular sections. To
Figure 10-7.Cross-section plots of stations 305 and 306
noted in figure 10-6.
Figure 10-6.Field notes for irregular sections.