In this exercise, you will use speed tables to draw a curve system for another part of the main roadway alignment. The design intent is to superelevate this roadway curve. Copy the Canada06 speed table to create a new speed table based on a design speed of 110 km/hr and 1000 m radius curve.

1. On the View menu, click Named Views to display the View dialog box. Under Name, select 4, click Set Current, and then click OK.

2. On the Lines/Curves menu, click Speed Tables Edit Speed Table to display the Select Speed Table dialog box.

3. From the Speed Table list, select canada06.sup, and then click OK to display the Horizontal Speed Table dialog box.

4. From the Design Speed list, select 110 km/hr.

5. Click Save As to display the Save Horizontal Speed Table dialog box.

6. Enter Tutorial for the File name, and then click Save to return to the Horizontal Speed Table dialog box.

7. Click in the eighth row of the Speed Table (1000 m radius curve), and then click Edit to display the New/Edit Speed Table Item dialog box.

8. Enter 350 for the 4 Lane Spi A value, and then click OK to return to the Horizontal Speed Table dialog box.

9. Click Save, and then click OK.

   Use the following steps to draw a new 4-lane curve system based on the Tutorial speed table for the main roadway alignment.

10. On the Lines/Curves menu, click Speed Tables Create Curves.

11. Select the left tangent, and then select the right tangent to display the Horizontal Speed Table dialog box.

12. Verify that Tutorial.sup is the current Speed table and 110 km/hr is the Design speed.

13. Click in the eighth row of the Speed Table column (1000 m radius), and then click OK to display the Select dialog box.

14. Click Four Lanes to create the spiral-curve-spiral system.

The tangents are connected with a curve system generated by the new speed table.

Click here to see an illustration of the speed table curve system.