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PUBLIC WORKS — STREETS CIP <br />The City of Orono has over 48 miles of streets. The actual life of a road depends on several factors including <br />the quality of construction, the amount of traffic, soil conditions, drainage, and the types of material that are <br />used for construction. For a well constructed bituminous street, a typical life cycle includes seal coating the <br />surface of the roadway every 3 to 7 years, a mill and overlay at year 15 to 20, and reconstruction at year 30. <br />As indicated above, there are different preventative maintenance methods that can be used to maximize the life <br />of a pavement. Two of the most common and effective methods include seal coating and mill and overlay. <br />The effectiveness of each of these methods is dependent upon the condition of the pavement and the type, <br />extent and severity of the pavement distress present. <br />Seal Coat <br />As the City is aware, a seal coat consists of the application of emulsified asphalt and loose aggregate <br />to the existing surface. After the specified "curing" time, the excess aggregate is swept up and <br />removed. <br />This rehabilitation method is typically used several times throughout the life of a pavement. Seal <br />coats are most effective when used on pavements in relatively good condition. This method is used to <br />provide a new driving surface and to re -seal the pavement surface to provide some protection from <br />weathering. The useful life of a seal coat is generally 3 to 7 years depending on the type of materials <br />that are used and the condition of the pavement to which it is applied. <br />The advantages of seal coating are as follows: <br />• Relatively low initial capital expense <br />• Provides improved skid resistance <br />• Provides some moisture protection to the pavement <br />• Minimal disruption to traffic <br />• Provides an aesthetically uniform surface <br />The disadvantages of seal coating include the following: <br />• Does not improve structural integrity <br />■ Short useful life <br />• Requires patching and sealing of major cracks prior to application <br />Limited effectiveness on pavements in poor condition <br />10 <br />