This article is part of a continuing series The Times is running between now and the upcoming property tax election in May. This article provides information related to the proposal to provide an additional $4 million per year for street maintenance.

Buy a new sponge and it comes out of the package nice and pliable, but leave that sponge out in the sun for a while and it dries out, becoming brittle, prone to crumbling and cracking.

The sponge is a comparison that can be used when talking about asphalt pavement maintenance, which is a large component of the proposed primary property tax to be voted on in May. Of the $7 million annually being asked for by the town, the plan is to use $4 million each year to upgrade the asphalt management program. That would provide $6 million per year for street maintenance alone, an increase from the current budget of $2 million.

Keeping the town’s paved streets smooth and safe requires a program of maintenance to keep the asphalt from drying out, cracking and crumbling.

The flexibility of asphalt allows it to remain adaptable to the temperature swings from extreme heat in the summer to Sonoran Desert cold in winter. As it dries out it becomes less flexible, and dry, brittle asphalt crumbles away – leaving cracks and potholes.

The typical lifespan of an asphalt roadway is 20 to 25 years, but with a proper maintenance plan that life can be stretched up to 40 years, particularly in this climate that does not have extreme freeze conditions. Most of the streets in Fountain Hills have either surpassed that age or are rapidly approaching it.

It is also believed many of the streets built prior to incorporation under Road Districts were built substandard to begin with, and the town’s maintenance has not been an optimum program for longest life, particularly in recent years as work has been deferred.

The town has used a management program that divides local streets into seven zones with paving maintenance scheduled to be done in a new zone each year, starting over when all seven areas have been completed. Funding issues resulting in postponing maintenance has put the town far behind in keeping up with the zone scheduling. In fact, the town has spent about five years just trying to complete Zone 1 in the current cycle.

This situation has prompted the town council to authorize staff to abandon the zone programming and implement a “worst is first” approach. A study is currently underway to examine pavement conditions as well as the underlying base to determine a priority schedule for maintenance. Results of that study are expected to be available in late April, before the election, but not before voting begins.

Catching up

With pavement management being a cyclical process, it is easy to recognize the ongoing costs on an annual basis. But at some point the town may catch up with the worst conditions, resulting in reduced annual costs for maintenance. Both Town Manager Grady Miller and Public Works Director Justin Weldy believe that is possible; however, neither could make a guess how soon that might be. Miller also points out that pavement management relies on one of the most cost-volatile commodities that exists – oil.

It is possible that bonds for individual pavement projects could be done, just like was done for the Saguaro Boulevard reconstruction and a portion of the Shea Boulevard resurfacing. In fact, it may be likely that once the Saguaro bond is paid off the town will ask voters for another bond for street work. However, it should be noted that these would be major pavement or reconstruction projects like Saguaro and Shea. Ongoing maintenance, such as the routine sealing application, is by law prohibited from bond funding.

Maintenance plan

There are four components to asphalt maintenance. Those include crack seal, asphalt emulsifier, slurry seal and mill and overlay.

Crack seal is an ongoing process for asphalt to keep moisture from seeping underneath the pavement and causing greater damage. Crack sealing is often done prior to slurry seal.

The emulsifier is a thin seal of emulsified asphalt with ground tire rubber. It helps preserve the oils in the asphalt, keeping it flexible. It is generally the first layer of maintenance on the asphalt and something Saguaro and Shea boulevards, reconstructed in 2014/2015, will need soon with an estimated $500,000 price tag just for that.

Slurry seal is a combination of the emulsified asphalt and fine aggregate, usually sand. It is applied to local collector streets that get heavier traffic than residential streets. It replaces fine aggregate, protects the original surface and provides a new wearing surface.

Microseal is similar to slurry seal but is used on arterial streets where there is heavier traffic. It uses heavier, coarser sand and a polymer-modified emulsion.

Mill and overlay is done when significant portions of the roadway have signs of structural failure, potholes and significant cracking.

The asphalt surface is milled down to a good pavement base and new pavement is laid down to create a new road surface. This has been done with some frequency in Fountain Hills over the past five years.

In some cases, as it was with Saguaro Boulevard, there are portions in which all asphalt is removed and the subgrade replaced before putting down the new pavement.

Replacement of damaged and old concrete curbing and gutters is also part of the pavement management program.