Agenda - Public Works Committee - 07/19/2022

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bituminous pavement plus an inch or two of underlying aggregate base, leaving all or most of the reclaim material on site as a thicker aggregate base section, then paving a single 2-inch lift of bituminous pavement over the compacted reclaim material, which would generally provide a pavement section similar or slightly better than pavement sections constructed up to the early 2000's that generally met a 5-ton pavement design strength. Whereas today's standard street reconstruction projects involve reclaiming the existing bituminous pavement plus an inch or two of underlying aggregate base, leaving 11/2-inch less reclaim material on site as aggregate base, then placing 31/2-inches of bituminous pavement on top to meet a 7-ton design strength. Staff completed a deeper dive on costs associated with completing such "light" street reconstruction projects, which Staff now calls "reclamation rehabilitation" projects. Based on our latest calculations Staff estimates these projects will cost between 50 and 85-percent of a standard street reconstruction project. Therefore, utilizing reclamation rehabilitation projects would allow the City to reconstruct between 15 and 50-percent more streets than if standard street reconstruction projects are utilized. However, it is critical to remember that the anticipated useable life of streets constructed as reclamation rehabilitation projects would be between 25 and 40 years and would not allow an overlay of the pavement, while streets constructed as standard street reconstruction projects have an anticipated useable life of 60 years, which allows for 2 overlays. In addition, pavement design strength would be reduced which could cause issues during spring load restrictions requiring increased enforcement actions by Ramsey PD and other Staff. Staff can support this option if the Committee feels the benefits received from completing 15 to 50-percent more street reconstruction projects having useful lives between 20 and 35 years less, and generally having a 2-ton reduction in pavement design strength, outweighs the increased costs associated with completing standard street reconstruction projects. If reclamation rehabilitation projects are utilized, Staff will need to inventory these streets separately from all others to ensure they receive proper maintenance on a regular basis. Advancing Street Reconstructions to Overlay Improvements Staff further explored whether streets identified as street reconstruction projects in later years of the CIP having PASER values higher than 4 may be suitable for pavement overlay improvements in earlier years to extend the life of the pavement enough to allow the street to be reconstructed after the street reconstruction bubble passes to help prevent a similar street reconstruction bubble in the future. Attached to case #13332 are four figures showing streets with PASER ratings between 5 and 8, any of which could potentially be identified in a 10-year CIP as street reconstruction projects closer to the end of the 10-year period based on projected pavement decay curves, underlying soils, etc. Staff reviewed the 2022 — 2031 CIP to identify streets with PASER ratings between 5 and 8 that might meet this qualification. Staff only found one street segment that provided enough benefit to outweigh the additional cost due to overlaying a pavement section past the point of achieving 15 or more years of pavement life following an overlay. Staff therefore continues to assert that there is enough value associated with this option to pursue it any further at this time. However, Staff will continue to monitor this in future years and will pursue this option if and when it makes sense to do so. Temporarily Increase Street Maintenance Budget Staff estimates there are 19 miles of streets across the City that are experiencing significant surface stripping but are not identified for overlay or reconstruction improvements in the 2022-2031 CIP. Pavement on these streets will be prone to accelerated deterioration due to water pooling in the surface depressions, which is then forced between the pavement base and the wear courses as vehicle tires drop into the depressions and push the water into pavement voids. The rideability on these streets will also continue to decline while other streets are receiving overlay and reconstruction improvements. Staff therefore recommends spray patching these streets while PMP projects in the 2022-2031 CIP are completed, and as streets constructed between 1975 and 1985 having PASER ratings of 4 or less that are not included in the 2022-2031 CIP can be reconstructed. Based on 2022 bid prices, estimated costs for contracted spray patching on 19 miles of City streets having an