Enter the normal cross slope of the road when not in superelevation.

The normal cross slope you specify here is referenced by all of the superelevated curves in the alignment. Any changes you make to this field affect all of the superelevated curves. If you delete the normal cross slope, the superelevation is removed from the alignment.

Note: This normal cross slope value you enter is used in the Superelevation Diagram view. It does not replace the slope value specified in the corridor template instructions.

General

Enter the maximum rate of superelevation for the curve in terms of percent slope.

When you select a different field after entering a maximum superelevation value:

• The start station for the curve is automatically entered in the three Approach Station fields.
• The end station for the curve is automatically entered in the three Departure Station fields.

This provides a "baseline" superelevation with no transitions as shown in this superelevation diagram:

You can now enter different values in the Approach and Departure fields to define superelevation runoffs and tangent runouts for the curve.

Enter the length of the parabolic vertical curve that will be applied at each break point in the superelevated curve to smooth the transition. The software also draws these vertical curves in the superelevation diagram at the break points.

Join to previous

Enter the maximum distance that a compound superelevated curve can be separated from the previous compound superelevated curve and still be considered joined.

If the distance between two compound superelevated curves is equal to or less than this value, the two curves are joined so that appropriate superelevation is maintained throughout the two curves, providing a smooth transition.

Unjoined superelevated curves as shown in the superelevation diagram:

Joined superelevated curves:

Enter the maximum distance that a reverse superelevated curve can be separated from the previous reverse superelevated curve and still be considered joined.

If the distance between two reverse superelevated curves is equal to or less than this value, the two curves are joined so that appropriate superelevation is maintained throughout the two curves, providing a smooth transition.

Approach

Following is an example of the transition from normal crown, to runout, to runoff on approach to a fully superelevated curve:

Do one of the following:

• In the Runoff % in curve field, enter the percentage of the approaching superelevation runoff length that lies within the curve. The station is automatically calculated based on this percentage and the specified runoff length.
• In the Runoff % in curve: Station field, enter the station at which the superelevation runoff ends and full superelevation begins. The runoff percentage is automatically calculated based on this station and the specified runoff length.

Do one of the following:

• In the Runoff length field, enter the runoff transition length on the approach to the curve. The station is automatically calculated based on this length.
• In the Runoff length: Station field, enter the beginning station of the approach runoff transition. The runoff length is automatically calculated based on this station.

Do one of the following:

• In the Runout length field, enter the tangent runout length approaching the curve. The station is automatically calculated based on this runout length.

Note: The Runout length field is disabled if the Use runoff rate for runout checkbox is checked.

• In the Runout length: Station field, enter the beginning station of the tangent runout on the approach to the curve. The runout length is automatically calculated based on this station and the station specified for the approach runoff.

Do one of the following:

• Check to specify that the same transition rate that is used for the superelevation runoff also be used for the tangent runout. The software computes the tangent runout length using the transition rate based on the length specified in the approach Runoff length field.
• Uncheck to specify that the software calculate the tangent runout transition rates from the length specified in the approach Runout length fields.

Note: When the check box is checked, you can enter a station in the approach Runoff % in curve: Station and Runout length: Station fields. The software calculates values for the approach Runoff % in curve, Runout length, and Runoff length: Station fields. Use this feature if the project's superelevation plans give you the stations where the normal crown begins and ends, but do not give an intermediate station location where an adverse crown condition occurs (the outside lane has zero, or flat, cross slope).

Departure

Following is an example of the transition from runoff, to runout, to normal crown on departure from a fully superelevated curve:

Do one of the following:

• In the Runoff % in curve field, enter the percentage of the departing superelevation runoff length that lies within the curve. The station is automatically calculated based on this percentage and the specified departure runoff length.
• In the Runoff % in curve: Station field, enter the station at which the full superelevation ends and the superelevation runoff begins. The runoff percentage is is automatically calculated based on this station and the specified departure runoff length.

Do one of the following:

• In the Runoff length field, enter the runoff transition length on the departure from the curve. The station is automatically calculated based on this length.
• In the Runoff length: Station field, enter the ending station of the departure runoff transition. The runoff length is automatically calculated based on this station.

Do one of the following:

• In the Runout length field, enter the tangent runout length departing the curve. The station is automatically calculated based on this runout length.

Note: The Runout length field is disabled if the Use runoff rate for runout checkbox is checked.

• In the Runout length: Station field, enter the ending station of the runout length departing the curve. The departure runout length is automatically calculated based on this station and the station specified for the departure runoff.

Do one of the following:

• Check to specify that the same transition rate that is used for the superelevation runoff also be used for the tangent runout. The software computes the tangent runout length using the transition rate based on the length specified in the departure Runoff length field.
• Uncheck to specify that the software compute the tangent runout length using the transition rate that it calculates from the length specified in the departure Runoff length fields.

Note: When checked, you can enter a station in the departure Runoff % in curve: Station and Runout length: Station fields. The software will calculate values for the departure Runoff % in curve, Runout length, and Runoff length: Station fields. Use this feature if the project's superelevation plans give you the stations where the normal crown begins and ends, but do not give an intermediate station location where an adverse crown condition occurs (the outside lane has zero, or flat, cross slope).