Garner integrated three asset lifecycle models to coordinate pavement, sidewalk, and facilities projects
With a population just north of 31,000 people, the Town of Garner, North Carolina, has challenges common to small, established bedroom communities: a roadway network with 100+ centerline miles, aging water and sewer infrastructure, and a modest tax base from which to fund infrastructure improvements. Like any small town, Garner already needed to budget carefully to pay for capital improvements.
With the help of three asset-specific lifecycle models, Garner has gained the flexibility to explore short-term project options without sacrificing service levels or long-term financial goals.
The challenges of a reactive approach to asset management
Normally the final deliverable for a PCS is a report that includes the rating methodology and a table of street segments and distresses. Communities frequently sort these tables from most distressed to least distressed and pursue a simple “worst-first” repair strategy.
The trouble with the worst-first approach is no economy of density. The most distressed roadway segments aren’t always next to each other, but a “serious” segment could easily be surrounded by “poor” segments. By focusing on all the “serious” segments before moving on to the “very poor” and then the “poor” segments, local governments crisscross the community deploying crews and materials for projects. Doubling back to the same neighborhoods over and over again takes longer and costs more money, which means fewer miles getting treated each year.
A comprehensive pavement condition survey became a pavement lifecycle model
In 2022, WithersRavenel completed a pavement condition survey (PCS) for the Town of Garner’s 114 centerline miles of roadway. Using a nationally recognized distress identification manual, field crews rode along each street segment and catalogued the location, type, and severity of distresses.
In 2023, WithersRavenel kicked off a paradigm shift for the Town of Garner by transforming the PCS results from a static report to a dynamic lifecycle model. By incorporating the Town’s desired level of service along with the current pavement conditions and pavement management budget, the lifecycle model provided Garner with optimized budget scenarios. These scenarios were accompanied by a list of the exact streets, maintenance activities, and costs for each year of the analysis. By moving away from a worst-first approach, Garner will get to treat many more miles of road and keep good roads good with preventive maintenance.
Facilities added another dimension to Garner’s lifecycle modeling
Garner decided to expand its lifecycle modeling efforts to include a new asset class: facilities. This new class encompassed permanent buildings owned by the Town such as Town Hall, the Public Works Office, the Garner Recreation Center, police and fire stations, libraries, and park buildings.
WithersRavenel helped Town staff compile basic data about each facility’s installation date, life expectancy, and replacement cost.
To tailor the model to Garner’s specific concerns, WithersRavenel posed several questions:
- What is the appetite for capital improvements vs. maintenance?
- What treatment options would the Town consider for asset features like roofs, floors, and paint?
- What criteria trigger treatment?
- What are the unit costs for renewals vs. replacements?
The answers to these questions informed the model calibration and three budgeting scenarios modeled over a 30-year period:
- Current budget of $800,000 (with and without 3% cost inflation)
- Increased budget of $1,000,000 (with and without 3% cost inflation)
- Decreased budget of $400,000
The results showed how Scenario #1 – Current Budget would decrease service levels from Good to Fair and lead to a backlog of work with an average cost of more than $4 million until year 19, when it would decrease to about $2 million annually for the remainder of the model period.
Scenario #3 – Decreased Budget would perform notably worse, with service levels falling from Good to Poor and the backlog of work growing to more than $10 million annually by year 14. A decreased budget scenario is helpful for showing how bad things would get if funding were taken away.
Fortunately, Scenario #2 – Increased Budget would perform much better than Scenario #1 – Current Budget, decreasing the work backlog to nothing in year 12 and then holding steady at about $2–3 million annually until the end of the model period.
These results might sound conclusive—and sobering—but Garner staff quickly realized they were missing key a key piece of the puzzle: asset condition. Without this data, the model results had to be based on asset age. Age can be used as a proxy for condition, since older assets tend to be in worse shape, but actual condition data is better. After all, an old asset that’s still in good condition doesn’t need to be replaced, but assets in poor condition do need to be replaced regardless of their age.
In response, Garner authorized a facility condition assessment project. WithersRavenel is incorporating the results into the lifecycle model to yield updated recommendations.
Sidewalks connected pavements to places in the lifecycle model
In 2024 Garner added sidewalks to their lifecycle modeling mix.
Communities typically deploy field crews in a similar fashion to a pavement condition survey, focusing on the location and extent of concrete faults and broken panels. Communities are also increasingly collecting data about ADA compliance, such as sidewalk width and slope and the location and condition of curb ramps.
Garner used their lifecycle model to investigate the efficacy of their current sidewalk maintenance and replacement budget and explore alternative budgeting strategies to reduce work backlog and long-term costs.
By combining their sidewalk and pavement lifecycle modeling results, they were also able to identify opportunities to combine individual projects into more cost-effective programs, such as pairing curb replacements with streets that are due for resurfacing.
The bottom line
Garner leveraged integrated lifecycle models for pavement, facilities, and sidewalks to plan projects effectively, maintain service levels, and manage costs over the long term. A managed services contract with WithersRavenel will keep the models fresh and actionable, with regular updates to reflect infrastructure changes, new treatments, and funding adjustments. These services empower Garner to optimize their asset management program.