Abstract: The wheel force transducer of Michigan technology company (MSC) was used to collect the field truck data of tire load with different highway alignment, vehicle type, load, and pavement types. Combined with the vehicle dynamics, the characteristics of typical truck motion inertia load were analyzed. The results show that the magnitude of inertial motion load mainly depends on the vehicle mass, distribution, acceleration size, direction, and the number of tire groups and pressure. Highway alignment fluctuation and horizontal conversion would cause vehicle acceleration, deceleration, and complex inertial motion mode. The motion inertia load is divided into two types, with the first type being the large uniform load and another being the impact load. In the three directions, the value in the vertical direction is the largest, while the values in the longitudinal and transverse horizontal directions are small. The vertical impact coefficient can exceed 4, which is much higher than the impact coefficient commonly adopted nowadays. Sensitive locations with larger motion inertia loads are generally distributed in the turning sections and the slope bottom sections with significant changes in speed and driving direction. Long lasting impact is generally caused by rolling motion; Short time impact is caused by pitching motion and rocking motion, which is indirectly caused by vehicle braking or acceleration and deceleration on the vertical curve. It is necessary to consider the effect of truck motion inertia load in the design of heavy pavement structures and materials, curve design of bridge structures, and vehicle management.