OpenRoads Designer Tip: Pavement Preservation – Part 3

OpenRoads Designer includes several tools to evaluate existing geometric design conditions when projects are programmed for pavement preservation.

These types of projects are usually designated as “resurfacing.” Many other criteria are evaluated and may be included during the design process. Among them are:

• Mill and resurface only, EOP to EOP, no other improvements
• Corrections to horizontal and vertical alignment
• Cross slope or superelevation correction
• Resurface with pedestrian, bicycle, and transit facility improvements (widening)
• Resurface including shoulder pavement
• Resurface adding turn lanes (spot improvements)

This tip is Part 3 in a three-part series to consider when preparing a design as follows:

1. ON YOUR MARK (Alignments, Terrains, and Profiles)
2. GET SET (Templates, Edge Lines, and Corridors)
3. GO (Cross Slope Reports, Superelevation and Vertical Alignment Adjustments)

Part 3 – GO (Cross Slope Reports, Superelevation, and Vertical Alignment Adjustments)

Prerequisites

These articles are all developed on the following assumption: existing project data is available from a survey in a design file and contains existing features, existing longitudinal elements, and surface data. Although the discussion focuses on a two-lane two-way undivided facility, similar steps can be taken on multilane projects. Using the Corridor tools in ORD, a detailed Pavement Preservation Evaluation can be accomplished.

At this stage, all the needed Civil objects have been established. Let’s review them:

1. The Horizontal Geometry Alignment has been developed.
2. The Terrain data delivered from survey has been evaluated.
3. The Existing Profile Grade line has been developed.
4. The evaluations templates have been prepared.
5. The controlling edge lines have been built as features for Horizontal control reference.
6. The evaluation corridor(s) have been created.

Cross Slope Reports

Existing Cross Slope Reports can be generated in ORD to help with the project evaluation based on the following:

• Existing Lane Slope/Width Conditions – use this template to provide an evaluation of the existing lane cross slopes and widths along a specified interval of the alignment from the provided terrain. Template points are constrained to the existing surface vertically using one of several methods: Project to Surface, End Conditions, or Vertical Point Controls. A single component is needed for match existing conditions.
• Create Corridor – process or re-process the corridor with this template at an interval close to the distance that the terrain data was collected or greater.
• Point Controls – verify that the pavement edge features are controlling the horizontal width of the template components.

• Corridor Reports – use ORD > Corridor > Review > Corridor Report > Results Report to build a Corridor Modeling xml file that will be formatted in the Civil Report Browser.

• In the Bentley Civil Report Browser, on the upper left, open the Tools > Format dialog box and set the readout format options to your desired settings. Then close the dialog box.

• In the Civil Report Browser, on the left pane change the style sheet to TemplateDropsConstraints.xsl. This is a default style sheet delivered with OpenRoads Designer.

• In the Bentley Civil Report Browser, on the upper left, open the File > Save As > Microsoft Excel dialog box and save the report as .xlsx file format. Then save the dialog box.

• This report can now be opened with Microsoft Excel for further formatting and evaluation of the Existing Cross Slopes and Land Widths.

Superelevation

• Standard Superelevation rates and transition locations along the alignment can be calculated in ORD to help with the project evaluation.
• In the Models dialog, Create a new model in the DGN file named Superelevation.

• Switch to or Open the Superelevation Model in the DGN file.
• Attach the default Model of the DGN file as a reference. This Model will have the Alignment and Corridor to use for the Superelevation calculations.
• Use ORD > Corridor > Superelevation > Create > Create Superelevation Sections tool to build the Superelevation Sections for the Corridor.

• Select the evaluation Corridor, the Create Superelevation Sections dialog will open. Set the appropriate Parameters for the project Alignment.

• The Superelevation will be calculated and displayed in the Superelevation Model.

• Switch back to the Multi-Model Views.

• Attach the Superelevation Model of the DGN file as a reference. This Model will have the Superelevation calculations for the Alignment and Corridor.
• Use ORD > Corridor > Superelevation > Calculate > Assign To Corridor tool to apply the Superelevation Sections to the Corridor.

• Select the Alignment and Corridor at the prompts, then select OK on the Associate Superelevation dialog.

• This will add the Vertical Point Control overrides as Point Controls in the Corridor Objects dialog.

• Switch out the Corridor – Existing Cross Slopes template with a Cross Slope Correction Milling and Overlay Template along the Alignment range to build a Corridor model that meets the current standards for Superelevation.
• Depending on the project, evaluation and criteria for the superelevation rate and transition locations can be modified by editing the Superelevation model.

Vertical Alignment Adjustments

• So far, we have been evaluating the Corridor using the Existing Profile or the best fit profile from the first part of this series.
• To help mitigate the amount of Milling or Overlay needed, the Overlay Vertical Adjustment tool in OpenRoads Designer can be used.

• On the Overlay Vertical Adjustment tool, set the parameters to help limit the Overlay and set a Maximum Milling value.

• Once the parameters are set in the dialog, follow the prompts to accept, using left-clicks, until OpenRoads Designer creates a new profile.
• Open the profile view for the Alignment and review the Profiles to use for evaluation along the project corridor.

• The adjusted profile can now be used along the resurfacing to evaluate areas that cannot exceed a maximum milling depth.
• Depending on the evaluation and design criteria, parts of each profile may be needed for the final corridor. Use the Profile Complex by elements tool to build the final profile.
• All profiles can be saved as xml files as needed for building finished corridors.

Using the OpenRoads tools described in Parts 1-3 for evaluating and building alignments, profiles, and templates; designers can now go about making the final decisions to build the construction corridor.

Vern Danforth

Vern is a senior Transportation Engineer and has worked in the industry for several decades. He developed a passion for Computer Aided Design while obtaining a master’s degree in civil engineering at Purdue University. His experience spans across all civil technical areas on survey data, geometry, geotechnical, drainage, traffic plans, structures, and utilities. He has trained and supported many engineers and designers over the years on civil applications like GEOPAK, InRoads, OpenRoads, and Civil3D.