At its March 15 work session, the Wyoming City Council discussed possible strategies to begin implementation of its pavement management plan.
During a work session after the council’s previous meeting on March 2, Wyoming City Engineer Mark Erichson summarized a recently completed pavement management study. The objective of the study is to inspect and rate condition of the pavement and determine the most cost-effective strategy to systematically improve the roads. When the repairs take place is an important part of the strategy.
Engineering firm WSB and Associates began inspecting the city’s paved streets in November 2015. The city has 57.99 miles of paved roads, which are split up into 638 distinct paved street segments for the purposes of road repair. The length, width and area for each segment were determined. Besides visual inspection of the road surface, soil borings were taken on some of the streets.
Erichson explained that the number of cores taken depended on how the pavement surface looked. In instances where soil borings were not taken for the pavement study, they will be taken as part of the feasibility studies for future street repair projects.
In analyzing the roads, WSB rates roads on an overall condition index, which assigns road condition on a scale from 0 to 100. An OCI rating of 100 indicates a new road with no stresses. A lower OCI reflects poorer condition of the road segment.
Roads were categorized by OCI ratings: excellent (90.1-100), good (60.1-90), fair (35.01-60) and poor (0 -35). The report included pictures of specific city streets to illustrate examples of the OCI ratings and detailed the proportion of city streets that fall into each category. Streets rated excellent comprised 16.91 miles (29.26 percent) of Wyoming’s roads, compared to 23.92 miles (42.25 percent) of good streets, 9.3 miles (16.03 percent) of fair streets and 7.86 miles (13.55 percent) of poor streets. The current OCI overall average of all the city’s streets is 70.46 percent. The average city street is about 20 years old.
The recommendation for roads rated excellent was preventive maintenance and chip seal. WSB recommended mill and overlay for good roads, condition monitoring for fair roads and reconstruction for poor roads.
Erichson said pavement begins to deteriorate shortly after construction at a fairly constant rate. However, as it ages, it deteriorates more rapidly. If not maintained at all, pavement has about 20 years of useful life.
Maintenance costs increase as pavement gets older, explained Erichson, which means that implementing preventative maintenance strategy is most cost-effective. What this means for Wyoming, he said, is that the streets reconstructed in 2015 should be getting a first seal coat in 2017, then again in about 15 years. Overlay should be done at about 40 years, and some additional seal coat can help these roads last 60 years.
A final part of the pavement study included cost estimates to improve each street segment. In the executive summary, the average annual budget amount to maintain the OCI average of 70.46 of the streets would be about $1.03 million. In improve the overall OCI average to 75, an average annual budget of $1.89 million would be needed.
A plan year chart, which detailed annual budgeted amounts needed to maintain the streets at the current OCI, shows larger budgeted amounts in the first two years of implementation. To maintain the status quo, this means in year 1, the city would need to spend about $821,000, followed by $2.38 million in year 2 and between $775,000 and $993,000 thereafter.
The repair and replacement has to be completed on staggered schedules because the city cannot afford to make all the needed repairs at the same time. The council talked about the importance of making sure that projects to improve poor streets also accommodate maintenance of good ones. Factors determining choices include the city budget and whether or not some of the streets qualify for Minnesota State Aid for Streets. Heavily used streets or key connecting roads qualify for some funds.
Alternative forms of funding will be needed for streets that are not part of MSAS. Street assessments may be considered.
Using the maps from the study, council members discussed areas of 245th Street and Fondant, just west of Highway 61, as possible projects. Improvements to East Viking Boulevard were also discussed. There were no recommendations made at the work session, but the issue will likely appear soon on a council agenda.
In other business, the council:
– Tabled until the next regular meeting a decision about audio and video equipment for the council chambers. An Americans with Disabilities Act requirement has been added to the request for proposals.
– Learned from the engineer’s report that staff met with the Department of Employment and Economic Development to get information about available grants that would help with street reconstruction. This is tied to a proposed expansion at Polaris.