Alignment Design Check Examples

Following are some examples of design check syntax.

The following examples demonstrate the type of parameters that can be validated using design checks. Use the examples as a basis to create your own custom design checks.

Note: Several design checks are included in the Autodesk Civil 3D templates in the ToolspaceSettingsAlignment and ProfileDesign Checks collections.

Minimum Straight Length

This design check validates that a straight is a minimum specified length.

Name	Straight Length >= 100
Type	Line
Formula	{Straight Length}>=100
Formula Description	Straights must be greater than or equal to 100.

Minimum Straight Length at a Design Speed

This design check validates that a minimum straight length is used at a given design speed.

Name	Straight Length >= 100 @ 45mph
Type	Line
Formula	IF({Design Speed}>=45,Length>=100,1)
Formula Description	If the design speed is greater than or equal to 45, the straight length must be greater than or equal to 100. Note: In the IF function, the ending 1 indicates that if the element meets both the design speed and length conditions, a true value is returned. A true value means that the element meets the design check, and no warning is issued. If the element does not meet one or both of the conditions of the design check, a warning is issued.

Design Speed On Curve Radius

This design check validates that a minimum curve radius is used at a given design speed. This design check is relatively complex, and combines several formulas into a single design check.

In this example, the minimum curve radius at eight separate design speeds is validated. When applied to an alignment, the design check checks the curve design speed value, and then validates that the radius is greater than or equal to the specified value.

Name	Design Speeds On Curve Radii (Multiple)
Type	Curve
Formula	IF({Design Speed}>=120,Radius>=750, IF({Design Speed}>=100,Radius>=500, IF({Design Speed}>=80,Radius>=300, IF({Design Speed}>=70,Radius>=200, IF({Design Speed}>=60,Radius>=125, IF({Design Speed}>=50,Radius>=80, IF({Design Speed}>=40,Radius>=50, IF({Design Speed}>=30,Radius>=30, Radius>= 0))))))))
Formula Description	If the design speed is greater than or equal to one of the specified speed values, the radius must be greater than or equal to the specified radius value for that speed.

Design Speed On Straight Length

This design check validates that the straight length is within a specified range at a given design speed. This design check is relatively complex, and combines a several formulas into a single design check.

In this example, straight length at five separate design speeds is validated. When applied to an alignment, the design check checks the straight design speed value, and then validates that the straight length is within the specified range.

Name	Design Speeds On Straight Lengths (Multiple)
Type	Line
Formula	IF({Design Speed}>=120,(2000>=Length)*(Length>=500), IF({Design Speed}>=100,(2000>=Length)*(Length>=400), IF({Design Speed}>=80,(1500>=Length)*(Length>=350), IF({Design Speed}>=70,(1200>=Length)*(Length>=300), IF({Design Speed}>=60,(1000>=Length)*(Length>=250),Length>=0)))))
Formula Description	If the design speed is greater than or equal to one of the specified speed values, the straight length value must be between the maximum and minimum values specified for that speed.