05/29/19 City Council Agenda Packet - Work Session

Home Browse Search

PW Engineering Roles Public Works Engineering receives projects proposed for preservation from the Maintenance Division three years in advance of planned construction. Engineering performs field investigations to confirm treatment needs and reviews historic data on construction and maintenance of streets. Streets are then prioritized for detailed pavement testing and design recommendations based on the available funding and the assessed condition of the streets. Pavement testing and design reports identify whether a street needs to be reconstructed or rehabilitated (overlaid) and the range of treatment options available. If a street requires a full reconstruct,it is typically deferred until funding is identified. Public Works Engineering is responsible for capital project management including design, stakeholder coordination and communication, contract administration, and construction management. Public Works Maintenance receives updated construction costs from Engineering and utilizes this data for analysis and reporting of projected backlogs. Reports are based on a system-wide approach, not at the project level performed by Engineering. Treatment Types Treatments reflected in the backlog analysis are limited to three types: slurry seal, overlay,and reconstruct. Slurry Seal:The slurry seal option allows for a cost-effective treatment to seal the surface and restore the skid resistance of local streets, which do not carry high traffic loads. This treatment is not used on streets which require strengthening or reconstruction. Typical slurry seal costs include street cleaning, removal of vegetation, minor base repairs (dig-outs), sealing of cracks, and application of an emulsified asphalt-aggregate mixture to the entire paved surface. Associated costs include replacement of striping and pavement markings, and other work needed to return the street to normal operation. Overlay:Typical overlay rehabilitation costs include milling of existing pavement to a moderate depth to remove existing cracking and increase the strength of the structural section. Isolated areas of severely distressed pavement are removed and replaced including a new aggregate base. Associated costs include replacement of striping and pavement markings, adjustment of manholes, and other work needed to return the street to normal operation. Reconstruct:Typical street reconstruction costs include removal of the existing pavement and base structural section and replacement with a new structural section which will meet a 20-year design life. Isolated areas of curb and gutter are replaced where they would not be suitable to contain new paving or have severe drainage problems. The following table (Table 2) identifies the estimated costs for the various treatment types including costs to upgrade curb ramps to comply with The American with Disabilities Act (ADA).The slurry seal treatment is exempt from ADA requirements. Construction costs are updated on a bi-annual basis. 10 May 29, 2019, Work Session - Item B