Re‐exploring the AASHTO 1993 Method for a Cost‐Effective Pavement Design in Manitoba

Pavement structures costs constitute to the majority of the total costs of highway construction projects. Therefore, it is important to optimize each pavement structure to avoid an under‐deign or overspending on any project. In the past, Manitoba was using the Benkelman Beam Rebound (BBR) deflection method for the rehabilitation design. A mixed approach, together with several environmental and structural adjustments, was used in pavement design for the new construction or reconstruction projects. The assumed or estimated values of subgrade and layer materials stiffness did not well represented the materials those are in place or use in Manitoba. These led to an overdesign for most rehabilitation and some new construction projects.

Due to several limitations of the AASHTOWare Pavement ME Design approach, that yet to be resolved, Manitoba has undertaken major changes to its existing design practices for cost‐effective pavement structures. These include the use of more reliable/reasonable design traffic loading, layer materials and subgrade stiffness and drainage properties, pavement drainage condition, subgrade soils frost susceptibility, serviceability and reliability. As a result, significant cost savings are being realized. This paper presents an overview of Manitoba’s new approach and outcome to share with other agencies, designers and students.


Ahammed, M.A.

Session title

Innovations in Pavement Management, Engineering and Technologies


Pavements Standing Committee







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