Roadway Design Standards

Using the Superelevation wizard, you can specify roadway design standards, including superelevation attainment method, minimum radius, and transition length values.

Roadway design standards are contained in the design criteria file. You can customize the design criteria file to reflect your local standards using the Design Criteria Editor dialog box.

The XML-based design criteria file stores the standard tables and formulas that you can use to calculate superelevation rates and superelevation critical stations on an alignment. 

Superelevation Rate Tables

A table of superelevation rates that you can apply to different types of roadways as a function of curve radius and design speed.

Transition Length Tables

A table of values you can use in the Superelevation Attainment Method formulas. You can use the table to calculate the distances between the critical superelevation transition points for different types of roadways as a function of curve radius and design speed. In many cases, the transition length tables provide the actual length of transition of superelevation runoff.

Superelevation Attainment Methods

Specifies how superelevation is applied, and the method that is used to calculate superelevation critical stations for different types of roadways. Each defined method specifies the formulas used to calculate the distances between the critical superelevation transition points.

Autodesk Civil 3D supports two methods of superelevation attainment.

• Standard. Requires removal of adverse crown. This method is typically used on undivided, crowned roadways and divided roadways with crowned or planar sections.

• Planar. Does not require removal of adverse crown. This method is typically used on undivided, planar-section roadways, such as ramps and service roads.

In the design criteria file, each attainment method, superelevation rate table, and transition length table have unique, defined names.