1. © 2009 Bentley Systems, Incorporated Derricke Gray GEOPAK Product Manager Intersection Design with Roadway Designer

2. © 2009 Bentley Systems, Incorporated 2 | WWW.BENTLEY.COM Intersection Design Designing an intersection can be a complex and iterative process. There are an abundance of criteria to consider such as min/max slopes, stopping sight distance, drainage and R/W constraints – just to name a few. There are many techniques in Roadway Designer that can be used to model intersections. This presentation will cover the basic workflow used to model an at- grade intersection. 2

3. © 2009 Bentley Systems, Incorporated 3 | WWW.BENTLEY.COM Project Review 3 CL-278 Reloc-2 NW NE

4. © 2009 Bentley Systems, Incorporated 4 | WWW.BENTLEY.COM Project Review Before we begin, let’s review our project data and the template that we’ll be using. 4

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6. © 2009 Bentley Systems, Incorporated 6 | WWW.BENTLEY.COM Design Corridors The first step in the process is to design the separate corridors for the mainline and the side road. 6

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8. © 2009 Bentley Systems, Incorporated 8 | WWW.BENTLEY.COM Intersection Design Now that we have designed our corridors, we are ready to begin work on our intersection. First, we need to produce our curb return geometry, both horizontally and vertically. 8

9. © 2009 Bentley Systems, Incorporated 9 | WWW.BENTLEY.COM Create Surfaces There are several ways to calculate curb return elevations. Vertical Offset from PGL Pavement Slope from PGL Elevation Calculate from Surface Model 9 For this exercise, we’ll demonstrate how to calculate the beginning and ending elevations of the of the returns from a model. In order to do that, we’ll first need to create surfaces for both of our corridors.

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11. © 2009 Bentley Systems, Incorporated 11 | WWW.BENTLEY.COM Design Horizontal/Vertical Returns Through the use of the Multi-Center Curve application, we can have GEOPAK design our preliminary Horizontal and Vertical curb return geometry. 11

12. © 2009 Bentley Systems, Incorporated 12 | WWW.BENTLEY.COM Design Horizontal/Vertical Returns The Multi-Center Curve application can create one- center, two-center or three-center compound curves at the intersection of two alignments. The applications creates a new horizontal alignment in the geometry database and, if desired, a vertical alignment as well. 12

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14. © 2009 Bentley Systems, Incorporated 14 | WWW.BENTLEY.COM Integrate Returns into Side Road Now that we have the horizontal and vertical geometry for our curb returns, we can integrate this geometry into the design of the intersection. 14

15. © 2009 Bentley Systems, Incorporated 15 | WWW.BENTLEY.COM Integrate Returns into Side Road Assign curb return alignments as Point Controls Increase the template drop interval through return Generate new surface for Reloc-2 and review 15

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17. © 2009 Bentley Systems, Incorporated 17 | WWW.BENTLEY.COM Integrate Returns into Mainline We also need to integrate the curb returns into our mainline surface with the same workflow as we used for the side road. 17

18. © 2009 Bentley Systems, Incorporated 18 | WWW.BENTLEY.COM Integrate Returns into Mainline Assign curb return alignments as Point Controls Increase the template drop interval through return Drop the end conditions and shoulder Generate new surface for CL-278 and review 18

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20. © 2009 Bentley Systems, Incorporated 20 | WWW.BENTLEY.COM Finished Model With our intersection designed, we can now create our finished model, which will integrate both corridors into a single model. 20

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22. © 2009 Bentley Systems, Incorporated 22 | WWW.BENTLEY.COM Components In the V8i SU1, we can take advantage of the new functionality of plotting ‘components’ when we create our model. These components allow us to visualize our model to much better detail. 22

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24. © 2009 Bentley Systems, Incorporated Derricke Gray GEOPAK Product Manager Intersection Design with Roadway Designer