Percent of street inventory maintained annually by preventive maintenance
Proper preventive street maintenance is critical to achieving smoother, long lasting streets. Without treatment, our streets deteriorate more quickly. Preventative street maintenance is ongoing, occurring over multiple decades with the intent that streets last upwards of 80 years. Thus, it is crucial that we track what maintenance was done, when it was done, and the current condition to be sure the right treatment is considered for the right road at the right time. Asphalt overlaying, thin surface treatments, and crack sealing existing surfaces are the primary components of the City's Preventive Maintenance program.
Older surface treatments become less effective as they age and progressively become less protective after about 10 years. Our Pavement Management Information System (PMIS) uses street condition data to prioritize, select, and track all major work done on the streets. Additionally, we are always seeking better performing street materials, enhancing construction specifications based on industry best practices, and making necessary adjustments to decision making processes to optimize the use of limited resources.
Cycles of preventive maintenance vary by the treatment. Asphalt overlays and crack sealing are done all year. Thin surface treatments are done in the spring and summer, starting in April or May and finishing in September.
As of fiscal year 2021, Austin’s street network consisted of about 2,556 centerline miles of streets which is just over 7,958 lane miles of pavement. This is enough road surface to drive across the continental United State two and a half times!
Growth is a challenge for the street preventive maintenance program. Until recently, the street network was growing by as much as 7-8% per year, largely due to annexations. Growth has slowed over the past couple years to 1-2% per year, generally due to new construction.
Public Work's goal is to treat every street in the City once every 10 years, meaning that we aim to provide preventive maintenance to 10% of the City's streets every year. There will be some years where we will not achieve that goal because we are working on a smaller number of streets that require more complex treatment. And there will be years where we exceed our goal because we are treating streets that do not require intensive care.
The street maintenance program was badly affected by COVID-19 in FY2020 but was able to recover and safely perform various types of maintenance in FY2021. Other variables affecting maintenance include wet weather (many types of street maintenance can only be performed when streets are dry). During the winter storm of 2021, Street and Bridge crews pivoted to providing emergency services and supporting first responders.
Prior to FY2020, the recent trend falls close to the annual preventive maintenance target of 10% of the City's street inventory. The available budget for street preventative maintenance determines the total lane miles we can maintain over a year
NOTE: To see the underlying data for this chart, please select the "View Source Data" link above.
Additional Measure Insights
Public Works applies the same standards of quality in street ratings equally across the City and entire City receives similar street maintenance treatments every 10 years.
There are, however, geographic differences which correspond to geology and age of the network that affect preventative maintenance planning. Expansive clay soils are a poor foundation for any structure including pavements. And, the core of older Austin which was developed much earlier has older streets that are generally in worse condition. Street conditions City-wide are fairly well balanced with the exception of the older areas of Austin most of which have still not been rehabilitated or reconstructed.
Measure Details and Definition
1) Definition: This measure tracks the percentage of lane miles managed by the City of Austin that had preventive maintenance completed.
2) Calculation method: We calculated this measure using the formula:
((Total number of lane miles that underwent preventive maintenance applications)/(Total lane miles)) * 100
3) Data Collection Process: Pavement Management Information System (PMIS) uses street condition data to prioritize, select, and track street preventative maintenance (SPM) treatments and all major work done on the streets. Work completed by in-house crews is also tracked in a work order (maintenance) management system (MMS) called Maximo. Completion of both in-house and externally contracted street work is stored in the PMIS as project history.
4) Measure Target Calculation: Austin has been fairly aggressive about street preventative maintenance over the years. And the value of SPM has been well known by pavement experts for decades. Our ultimate goal is to keep an active (still functioning as intended) surface treatment on all streets as all times. Many of our current treatments can last about 10 years so if we set a goal of resurfacing about 10% of the network each year we can get back around to every street once every 10 years.
5) Frequency Measure is Reported: Annually (Fiscal Year)
Date page was last updated: January 2022