Like many agencies, the methods by which the pavement network is managed and maintained in The City of Calgary (The City) have evolved substantially over the past decades. At one time, the process was limited to visual windshield surveys, often by a construction superintendent or reaction to public complaints. Later, the development of more sophisticated pavement assessment tools enabled a more systematic Pavement Management System (PMS) approach. Currently, The City utilizes the Municipal Pavement Management Application (MPMA), which was developed in the early 1980s by the province of Alberta. MPMA is used to assess the status of the pavement network, estimate the maintenance and rehabilitation needs of the network, and develop roadway rehabilitation programs based on user-defined budget constraints and Pavement Quality Index (PQI). Around 2003, The City saw the need to expand upon their network-based assessment activities with a project level evaluation process. This resulted in the development of a three-tiered approach. Tier 1 comprises a review of PMS data, possibly a windshield survey, typically resulting in standard approaches being applied to lower profile projects. For Tier 2 assessments, this effort is supplemented by a detailed visual condition survey and review of other available information. The subject of this paper is the Tier 3 Pavement Assessment program. In this case, available PMS information and a detailed visual condition surveys are supplemented by more in-depth evaluation. For a given project, this could include detailed traffic analysis, pavement thickness investigation using Road RadarTM, Falling Weight Deflectometer (FWD) structural assessment, and potentially, geotechnical investigation. The overall approach is considered to represent the state-of-the-practice for pavement evaluation. With the Tier 3 approach, the full spectrum of pavement strategies is considered, including maintenance only, mill and inlay, concrete pavement, concrete overlay, partial depth reconstruction, full depth reclamation, and pavement reconstruction. For some projects, more than one solution is deemed most appropriate for different segments. For higher trafficked roadways in urban municipalities, materials selection is particularly important and premium surfacing materials, such as Stone Matrix Asphalt (SMA), and mixes using asphalt rubber and modified asphalt binders have been used when warranted. Over twenty Tier 3 evaluation projects have been completed to date. This paper will detail the assessment activities and process for development of rehabilitation strategies for two project-specific case studies where construction has been completed.
