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MINUTES OF THE ORONO CITY COUNCIL Tuesday, May 27, 2014 7:00 o’clock p.m. _____________________________________________________________________________________ Page 17 of 23 (11. WATERTOWN ROAD AND STUBBS BAY ROAD FEASIBILITY STUDY, Continued) Martini stated during the study they were looking at two options for improving Watertown Road. The first option was a one inch mill of the existing pavement and a three to four inch overlay. It was determined that that option had an estimated life of eight to ten years based on the condition of the existing pavement and subgrade. The other option looked at was a full depth pavement reclamation, which has an estimated life of 20 years with the belief that it could be extended with routine maintenance to the pavement section. Martini noted the City Council requested additional information to help in evaluating those two options. One of the items provided in the updated report is a graphic that is intended to show how pavement conditions change over the life of a roadway. Martini indicated the red colored line generally shows how the condition of a pavement changes with the life of the roadway. When the pavement is newer, the road is in excellent condition, with the condition of the pavement gradually dropping over the course of a number of years. The first 40 percent drop in the quality of the road occurs over the first 75 percent of the life of the road. The next 40 percent drop in quality occurs the next 12 percent of the life of the road. Martini noted the right half of the graphic depicts how the two options will likely play out over time. In the reclamation option, there is an initial spike in the condition of the roadway based on the improvements. As it relates to the improvements, under the reclamation process the existing blacktop along with the aggregate base will be removed, grinded up, and then laid back down. There will then be a new pavement surface laid over the top of that. Martini stated when you compare it to the mill and overlay, it resets the performance curve since the base of the road has been repaired and the life of the roadway basically doubles. If regular maintenance is performed, the life of the roadway may be up to three times the life expectancy of a mill and overlay. Martini explained under the mill and overlay option, the performance curve is not reset since the base of the roadway is not being replaced. Under the mill and overlay scenario, once the life of the mill and overlay is exhausted, then the pavement condition is back to a similar state as to what it is currently and a new discussion on what improvements should be made will need to occur. Martini stated ultimately they prefer to get 30 years of life out of the roadway. Under the reclamation option, the estimated total cost for 30-plus years would be $3.2 million, including some type of sealant and an eventual mill and overlay. The mill and overlay option for 30-plus years is $3.8 million, which includes the initial cost of the mill and overlay plus a reclamation somewhere down the road and preventative maintenance. Martini stated the important thing to remember when comparing the options is that under the mill and overlay option the majority of the costs occur over a 10-year period. Under the reclamation option, the preventative maintenance costs are extended over a longer period of time. Martini stated he would recommend the full-depth reclamation project, which would include reclamation of the existing material with a four-inch overlay, excavation and replacement of the sub-grade materials where there is significant distress, and replacement of drainage structures. Martini stated drainage is a key element to extending the life of the roadway. Martini noted a maximum of 20 percent of the underlying subgrade can be reconstructed before Municipal State Aid standards need to be met and that the initial costs for the reclamation project is projected to be around $2 million. Bremer asked if the 30 years is based on a general average or based on the conditions in this area. Item #03 - CC Agenda - 06/09/2014 Approval of Council Minutes 05/27/2014 [Page 17 of 23]