Example: Standard road width is 3.0

Example: Standard road width is 3.0 m . Design vehicle is a stinger-type log-truck with dimension as shown in Figure 30. Curve radius is 22m, deflection angle equals 60 .
From Figure 37 locate curve radius on the x-axis (interpolate between 20 and 25), go up to the corresponding 60 -curve (interpolate between 45 and 90 ), go horizontally to the left and read the vehicle off-tracking equal to 1.8 m.
The total road width is 4.80 m (3.0+1.8 m).
Depending on conditions, a safety margin of 0.5 m could be added . The current 3.0 m road width already allows for safety and driver's error of 0.30 m on either side of the vehicle wheels (truck width=2.40 m). Depending on the ballast depth, some additional shoulder width may be available for driver's error. Taper length would be 15 m.