Pavement Design

Pavement Design | LCCA Projects

District 3 LCCA Projects

District 3 Comments

SP 7102-146, US 10, Letting date 12/18/2026

Comment from Daniel Labo, Concrete Paving Association of Minnesota, djlabo@cpamn.com, 1/20/2024

Segment 1 Comments:

• Bituminous design shows 12” of engineered soil in the MnPAVE Flexible report. Based on the old construction plans found on EDOCS, the old concrete had 6” of gravel beneath it then native soils. However, that 6” of gravel is within the removal limits as noted in the typical section, so unless additional information is available to the district that they did provide in the review information, the 12” of engineered base should be removed from the design (as the old plans show it as a native soil). If this is correct, it would result in the bituminous design for this section changing to 6.0” and the select granular borrow reduced to 18” (keeping the same final surface elevation).

Segment 2 Comments:

• There are no MnPAVE design reports listed showing bituminous over FDR, so it is not possible to adequately review. Please upload the MnPAVE design reports for all segments, and provide an extension to allow for subsequent review following posting of these design reports.
• All segment 2 options show grade raises ranging from 6-7.5” (6.5”, 7.5”, and 6” specifically). The LCCA only includes the costs exceeding that of the least grade raise (0.5”, 1.5”, and 0” net respectively). While I don’t necessarily disagree with the approach taken in certain circumstances, this area is not a good place to use this approach as noted below. Additionally, MnDOT testified to the legislature that this type of net calculation should not be used in LCCA’s. Therefore, I believe MnDOT management would not approve of utilizing this method, and the total regrade depth should be included in all options; including subsequent work resulting from the grade raise impacts.
  • One big issue here is that the roadway needs to match into BR 5444, so transitions will be required (transitions are not the main issue). Raising the grade at this location is nowhere near as simple as the LCCA shows. As the overpass bridge has steep slopes (which the District has had several projects to repair and ultimately correct over the years, several of which I was personally involved with as a MnDOT employee), and any substantive grade raise will likely require complicated regrading with impacts to curb and gutter, vegetation, drainage structures, guardrail, HTCB, concrete median barrier, etc. I highly doubt that the cost of the most expensive option to regard is $9000/mile. The concrete option would be able to be constructed at the existing profile in this area, achieving significant cost savings. Why did the district ignore the full impacts of the grade raise at this segment?
  • When accounting for a concrete pavement constructed at grade, it is anticipated that the final LCCA for this segment will change dramatically; and the low LCCA option will most likely be concrete.
  • Will the district please provide adequate information to review this LCCA (such as pavement designs for this segment), and modify the LCCA segment 2 concrete option to be built at grade? What are the results?

Based on the comments of segment 2, review of the documents has ceased due to the critical issues highlighted. LCCA’s are most impactful when combined with design iterations to calculate alternative designs superior to initial designs. Concrete pavements allow for robust pavements to be built on substantially less granular structure, which can be leveraged here for substantial savings. The iteration proposed to segment 2 is an option that could save the District upwards of $1m on the total first cost to the project alone. Thank you for allowing public review and comment on the LCCA, and I am willing to assist the District with any follow-up questions that it may have regarding options for this project.

Pavement Design Engineer response

pending

SP 8001-44, US 10, Letting date 1/15/2025