Cross Slope Lane Matching

Inspired by the Advanced Daylighting post on the Being Civil blog I thought I would share a situation that come up at my company that made me put my thinking cap on.  In this particular case the designer wanted to control the RIGHT lane slope with two alignments – and of course profiles.  In addition, he wanted the LEFT lane to match the variable right lane slope.  Last but not least, both lanes would need to have the ability to have variable widths and the cross sections for the Corridor needed to center on the centerline of the road (in this example “Align 2”).

2009.11.16-Diagram of Need

To accomplish this task we made an Assembly that used:

1. an Offset Assembly

2. the LaneTowardCrown subassembly

3. the LaneOutsideSuper subassembly

4. and assembly Parameter References

A sketch of the assembly and how it needs to react looks like the below.  As “Align 1” – or “Align 2” for that matter – goes up and down the cross slope of the RIGHT lane changes and the LEFT lane needs to adjust to match.

2009.11.16-Sketch of Assembly

A picture of the real deal is as follows.  Note that everything builds off the Offset Assembly.  The assembly maker is just a place holder for the Sample Lines to center on the road centerline (Align-2).

2009.11.16-Assembly SetupNow, in the Assembly Properties dialog set the “LaneOutsideSuper” slope to reference the “LaneTowardCrown” cross slope (see image below).

2009.11.16-Assembly Properties

Essentially that’s it.  Now it’s time to setup the targets in the Corridor model.  The Offset Assembly would be set to “Align-01” and the crown point for the “LaneTowardCrown” subassembly would target “Align-02(the CL alignment).

2009.11.16-Corridor Setup

The final product should look something like the below.  You can validate that the lane slopes match through “View\Edit  Corridor Section…”.

2009.11.16-Final Product(Oops, missed the T in maTching…oh well)

THANKS … and I hope this helps.  🙂

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