Agenda Date: 04/15/2025
Subject:
Title
Pavement Preservation Program - 2025 Projects Overview
Body
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From: |
James L. Becklenberg, City Manager |
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Prepared by: |
Brent Soderlin, Director of Public Works & Utilities |
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Brent Thompson, City Engineer |
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Kimberly Dall, Assistant City Engineer |
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Presentations: |
Brent Soderlin, Director of Public Works & Utilities |
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Kimberly Dall, Assistant City Engineer |
PURPOSE:
Staff will present an overview of pavement preservation projects planned for construction in 2025.
LONG-TERM OUTCOME(S) SERVED:
Safe Community; High-Quality Governance
DISCUSSION:
The City of Littleton created its first comprehensive Capital Improvement Plan (CIP) in 2024. This plan provides a strategic framework to administer and implement projects and equipment acquisitions across the organization. The CIP identifies over 175 projects in the 5-year horizon of the plan, with $300 million in identified funding and another $158 million in needs without an identifiable funding source. Coordination with agency partners and others occurs to support comprehensive improvements in the community.
Pavement Preservation Program activities are funded capital projects. The trend of overall annual capital spending has increased. Budgets from 2019 to 2024 averaged $33.3M; the 2025-2029 budget average is 35% higher at $44.8M. The pavement preservation annual budgets are also trending upward. For the same time periods, the average budget for pavement preservation has increased 320%, from $2.3M to $7.5M averaged annually. The pavement preservation program will apply “the right treatment to the right street, a the right time” The following provides highlights to the pavement preservation projects to be constructed this year, at the right time.
BACKGROUND:
In 2025, big things are happening in Littleton. The city’s Public Works team has geared up for a busy year of large-scale capital road and infrastructure upgrades, powered by voter support of the 2021 Ballot Issue 3A, which raises funds for an increased pace of capital projects paving the way for transportation improvements, economic growth, and innovation. This year brings more projects to the community with the additional revenue from 3A and grant funds awarded.
The annual pavement preservation budget varies from year to year based on revenues and projects planned to be completed. The city created its first comprehensive Capital Improvement Plan (CIP) in 2024. This plan provides a strategic framework to administer and implement projects and equipment acquisitions across the organization.
The trend of annual spending has increased, the following chart shows the annual capital budget and a three-year trendline in millions of dollars. Budgets from 2019 to 2024 averaged $33.3M; the 2025-2029 budget average is 35% higher at $44.8M. The trend of annual spending in the category of pavement preservation has also trended upward. For the same time periods, the average budget for pavement preservation has increased 320%, from $2.3M to $7.5M averaged annually, shown by the black line in the chart.
Pavement preservation projects require coordination with stakeholders and community partners. Denver Water, Xcel, Littleton Public Schools, and other partners also perform capital work within the city. City staff coordinate the project work and timing, sometimes years in advance. This prevents newly paved roadways from being cut for waterline replacement projects, eliminates overlapping work zones during construction, and provides an opportunity to coordinate improvements for a greater impact of repairs for the roadway surfaces.
The annual pavement preservation treatments selected for Littleton’s approximately 360 lane miles of streets within the community’s transportation network are equally influenced by the condition ratings of the streets. Overall condition assessments have been occurring every three years over the full street network. The data collected supports the Capital Improvement Program team in the determination of the locations, along with specific preservation and mitigation practices, to preserve the condition of the city’s roadways and extend the useful life of the pavement.
Managed by the Engineering Division, the Pavement Preservation Program goal is to keep Littleton’s roads at a PCI of 75 or higher. The strategy is to identify the correct preservation treatment, and apply it at the right time, to extend the life of the pavement.
Surface sealing streets in good condition protects the wearing surface and prevents degradation of the street structure over time. Pavements that have not been adequately sealed and preserved require more intensive activities and repairs to bring the roadway back to a good condition. The degraded asphalt surface layer must be removed to the still-viable pavement and base below, then provide a new asphalt surface layer. Treatments that seal the surface are significantly less costly than surface replacement or roadway reconstruction activities. Staff must strike a balance between reconstruction and preservation activities to gain the most value of preservation funding allocated. Common pavement preservation treatments are described below.
Patching work repairs failed pavement areas across the community. The work is focused on street segments identified by Public Works, and typically is in advance of other pavement preservation treatments.
Milling is the removal of the top inches of a roadway to remove asphalt that is no longer providing a smooth wearing surface. An overlay replaces the spent layer removed, providing a new traveling surface. Localized areas of pavement failure may be encountered after milling. These areas will be patched prior to paving the surface.
Street reconstruction involves pulverizing the upper layers of the roadway into the subgrade, removing excess material, and recompacting the subgrade for the roadway. The street is then paved with specified thicknesses for the full street pavement section.
Streets that do not have a viable base or have a fully degraded surface must be reconstructed. Preservation techniques must consider the pavement distresses present to be effective; a surface seal will not improve the condition of a roadway that has a failing base layer.
The holistic program approach of “right treatment, right street, right time” effectively preserves the pavement network thorough leveraging low-cost preservation techniques to limit future reconstructions and provides the most value from the funding available for pavement preservation.
The Engineering Division obtains a pavement condition assessment every few years which assigns a Pavement Condition Index (PCI) rating based on the pavement condition, ranging from 0 to 100. A PCI of 100 corresponds to a new road, a PCI rating of 0 means the pavement has completely failed. The PCI rating drops over time; the rate of degradation increases with lower PCI ratings.
The full network assessment is a valuable tool in determining the right treatment for each roadway for preservation; however, Public Works staff inspect and verify the condition of a street before including the segment in a preservation program to ensure the roadway is receiving the right treatment at the right time.
Managed by the Engineering Division of Public Works, a primary goal of the Pavement Preservation Program is to keep Littleton’s roads at a PCI of 75 or higher. The strategy is to identify the correct preservation treatment, and apply it at the right time, to extend the life of the pavement.
Surface sealing streets in good condition protects the wearing surface and prevents degradation of the street structure over time. Pavements that have not been adequately sealed and preserved require more intensive activities and repairs to bring the roadway back to a good condition. The degraded asphalt surface layer must be removed to the still-viable pavement and base below, then provide a new asphalt surface layer. Treatments that seal the surface are significantly less costly than surface replacement or roadway reconstruction activities. Staff must strike a balance between reconstruction and preservation activities to gain the most value of preservation funding allocated.
The adjacent map shows the treatments for 2025, color-coded by treatment type. The outer blue line represents the city limits; purple lines indicate full roadway reconstruction; the red lines are designated for mill and overlay. And the small segment of cyan on the north end of Windermere is a chip seal treatment.
Over five centerline-miles of residential streets are slated for repair and a new top layer of asphalt this summer as part of the pavement preservation program.
Prior Actions or Discussions
The last pavement specific item presented at a council study session on 1/10/2023.
FISCAL IMPACTS:
Pavement Management projects of approximately $7.5 million annually are planned for 2025 - 2029.
STAFF RECOMMENDATION:
N/A
ALTERNATIVES:
N/A
Proposed Motion