Overloaded vehicles can cause severe damages to road infrastructures, thus the Malaysian government has implemented axle load limits. This paper studies the level of enforcement of the single axle load limitation in the northern part of the North-South Expressway and the existing load distribution. Five survey stations' axle load data were gathered. Via the analysis of the axle load data, it was found that overloading was a common and serious problem since it formed a significant percentage of the total number of weighted axles. It has been recommended that the level of enforcement should be increased to reduce maintenance cost and hazards caused by overloaded trucks.