Rate of shoulder at high side and low side of curve area (where superelevation takes place) can be assigned. The difference between high and low side with the calculation sample is shown below;                 

Example can be referred based on this Project File. 

Example is taken at Chainage 350, which full superelevation is at 6% and cross slope of shoulder is at 4%. 

Shoulder high side is the higher side of shoulder at the superelevated pavement.

Shoulder low side is the lower side of shoulder at the the superelevated pavement. 

Users can assign the pavement of the shoulder to fixed elevation or to follow carriageway rate. The settings can be changed in Parameter Settings.

Fixed Shoulder #

The shoulder slope is fixed based on the Shoulder Cross Slope (default: 4 %) continuous from the elevation rate.

Based on the example given in the project file at chainage 350, the carriageway rate is at 6% or 1:16.7 (full superelevation), shoulder cross slope is 4% and the shoulder width is 3.6 m. The calculation of ratio and the end elevation of each high side and low side are as below:

High Side:

Ratio : 6% (full superelevation rate) – 4% (shoulder cross slope)

= 2%

= 1:50

End Elevation : 26.786 – (2/100)(3.6) 

= 26.714 m

Low Side:

Ratio : 0% – 4% (shoulder cross slope)

= -4%

= 1:25

End Elevation : 26.354 + (-4/100)(3.6) 

= 26.210 m

Follow Carriageway #

The shoulder rate follows the carriageway slope rate regardless of the shoulder slope rate. 

Based on the example given in the project file at chainage 350, the carriageway rate is 6% and the shoulder width is 3.6 m. The calculation of ratio and the end elevation of each high and low side are as below: 

High Side:

Ratio = Same as superelevation rate

= 6%

= 1:16.7

End Elevation : 26.786 + (6/100)(3.6) 

= 27.002 m

Low Side:

Ratio : Same as superelevation rate

= 6%

= 1:16.7

End Elevation : 26.354 – (6/100)(3.6) 

= 26.138 m