Georgetown’s rapid growth means that our city street network continues to expand. The city’s road network currently has 704 lanes miles of city streets, which is three times larger than it was 25 years ago. This growth puts more demand on our budget for street maintenance funding.
Georgetown voters wisely supported a dedicated 0.25 percent street maintenance sales tax in 2002 and have voted to reauthorize the sales tax by wide margins every four years since then. The street maintenance sales tax on all goods and services sold in Georgetown generates more than $3 million annually that is used to fund street maintenance.
In the past, the City has used a variety of repair and resurfacing methods to maintain our city streets. Costs range from relatively inexpensive treatments like crack sealing for $1,000 per lane mile and surface sealants for $3,500 per lane mile to double-course chip seal for $42,000 per lane mile. More expensive treatments include hot-in-place asphalt recycling for $110,000 per lane mile, milling and new asphalt overlay for $127,000 per lane mile, and full-depth rehabilitation at $141,000 per lane mile. The City’s street maintenance strategy is to use lower cost maintenance methods in order to extend the life of pavement surfaces and avoid more costly full road rehabilitation.
In the last few years, we have heard residents express dissatisfaction with the use of traditional chip seal treatments that involve placing oil in one pass and small aggregate on a second pass. While this process served a purpose for many years, current community expectations coupled with better paving technologies mean that other methods may be better options for streets in residential settings.
As a result of resident feedback, the City Council directed staff to form a Pavement Management Review Committee to look at pavement management options and make recommendations. The Committee was comprised of members of the Georgetown Transportation Advisory Board and worked for six months to learn about and analyze pavement surfacing options. Working with Public Works staff, the Committee developed five scenarios using a menu of different types of pavement processes.
At a City Council workshop in November, Public Works Director Octavio Garza presented the five options with a Committee recommendation for one option. That option would retain the use of most treatment options used in the past. However, it would involve a few changes.
Double-course chip seal would no longer be used on residential streets, major collectors, or minor arterials. This means that double-course chip seal would not typically be used on arterials like Airport Road, D.B. Wood Road, Del Webb Boulevard, Lakeway Drive, Scenic Drive, Sun City Boulevard, Wolf Ranch Parkway, and others. The City Council did express support for the option of using double-course chip seal on major collectors or minor arterials that are not in residential areas.
Two new applications would be introduced. The first is an ultra-thin bonded wearing course. This application consists of a thin layer of specially-graded hot mix asphalt over an application of emulsion. The ultra-thin product can be applied in one pass and is suitable for many applications, including residential streets. It has an expected service life of 8-10 years and can quickly be applied with minimal traffic disruption. The cost is a bit more than double-course chip seal, but it is about half the cost of hot-in-place asphalt recycling.
Another type of application recommended by the Committee includes high-performance pavement sealants. These high-performance sealants are twice the cost of the sealants the City has used in the past, however, they have a longer life span and are suitable for many applications, including residential streets.
In the November workshop, Garza also explained the Pavement Condition Index, or PCI, and how it is related to the pavement maintenance program. The City hires a specially-outfitted vehicle to drive every street in the City and, based on factors like cracking and surface condition, assigns a score from 0 to 100 for each road segment. These scores can then be averaged across the entire road network to determine an overall PCI score for City streets. By policy, the goal of the street maintenance program has been to maintain an overall PCI score of 85 for the City street network. Due to the size and age of the City’s road network, Garza explained that the street maintenance budget would need to double from $3.3 million to more than $6 million in the coming years in order to maintain a PCI of 85 for city streets.
At the November workshop, the City Council gave positive feedback to the Committee’s recommendation. In the spring, Public Works will present a maintenance plan to the City Council that includes the new applications to be used next summer. These adjustments to the street maintenance program should result in products with better performance and help us to meet the goal of maintaining our City road network.