The University of Waterloo’s Centre for Pavement and Transportation Technology (CPATT), the Ontario Ministry of Transportation (MTO), the Natural Sciences and Engineering Research Council of Canada (NSERC), the Ontario Hot Mix Producers Association (OHMPA), Stantec Inc. and McAsphalt Industries Ltd. are collaborating to evaluate the performances of three flexible pavement designs, including two perpetual/long-life (with and without the rich bottom mix (RBM) layer) and one conventional pavement designs. The three flexible pavement designs are being monitored by strain, pressure, temperature and moisture sensors, which are installed in the asphalt, granular and sub-base layers. Two types of piezoelectric weigh-in-motion (WIM) sensors were installed in the surface course of the perpetual pavement (with the RBM layer) in order to capture the axle loads distribution. Thus, load, strain, vertical pressure and environmental parameters affecting the pavements’ performance can all be monitored and used to evaluate the pavement mixes under Ontario’s climate and traffic conditions. This paper reports on the WIM installation and calibration efforts and investigates the preliminary results of data analysis of two types of piezoelectric WIM sensors in the period after sensors’ calibration. An auto-calibration algorithm for the most effective piezoelectric WIM sensors will be provided in the future to supply calibration factors for Ontario’s climate and for high speed, high volume roads, while collection of WIM data will provide an opportunity for investigating the load spectra impacts on the pavement designs.