Modeling Plan

Jeff's Project Goals for the Electronic Workflow

Set up InRoads engineering and CAD settings that work well with the "aerial-accuracy" topos we currently have and will provide solutions with little re-work when more accurate information becomes available.  Minimize Re-work.

Engineering Assumptions and Plan

We'll set up some InRoads v8.9 templates that can be run from either the centerline or from an EOP or outside lane line or all... 

The following are my understanding of the engineering constraints to be honored in the model.  Please correct me if I've made some incorrect assumptions.

Accuracy

The proposed solutions are only as accurate as the existing conditions model, which at this time is limited by the accuracy of the existing surface, which is derived from an aerial survey.  The improved accuracy of ground surveys will increase the accuracy of the proposed model, perhaps leading to different solutions.

Typical Sections Constraints

Zero Slop Middles?

I (Jeff Martin) assume that in most cases the typical section will be build with "zero slop" in the middle.  In areas where widening may occur, the middle areas are geometrically as tight as possible and everything builds outward from there.  Critical issues:

•  making sure the right dimensions are used.  Some of the Typicals start their dimensioning from a center Barrier Type 60.  Is this dimension fixed?  What if a different barrier is used?  This will throw all other dimensions off.  For example if the opposing road surfaces are vertically offset a Type 60C may be required, which has a width greater than the standard 24."  Such excess will be taken from the interior shoulders.
• What's the horizontal anchor point?  Probably one of the interior sawcuts.

Independent Widenings

(or Slop middles, where there extra room in the middle).

New Pavement slopes

in increments of 0.5%, depending on the slope of the existing pavement.

Sawcuts

Sawcuts will vary based on engineering judgment.  Initial runs will be based on proposed horizontal geometry requirements only.   As the sawcuts are modified for driveability, transverse geometry will vary correspondingly.  Templates will have to be modified to follow sawcut alignments rather than "constant offsets."