Mot bakgrund av ökningen till 74 ton max bruttovikt för fordon på vägar och en trolig utveckling mot ännu högre laster har deformationer i terrass och geotekniska konstruktioner identifierats som ett problem. Deformationer i terrass och geotekniska konstruktioner kan leda till mycket stora kostnader i framtiden för underhåll och punktvisa förstärkningsåtgärder. De höga kostnaderna är förknippade med att orsaken till skadorna återfinns djupt ned i vägkroppen och kräver omfattande åtgärder. Orsaken till att 74 ton anses som en risk är att andelen trippel-boggie (max 24 ton) kommer att öka på vägnätet. Detta innebär att enskilda axellaster minskar men djupt ned i terrassen överlagras påkänningarna så att dessa kan överskrida de som tillåts för drivaxeln (11,5 ton). Det bör poängteras att det svenska vägnätet till stor del består av vägar som byggts för helt andra belastningar än vad som i dag förekommer. This report presented the theoretical analyses of the impact of heavier and longer vehicles on the subgrades of pavement structures. Since heavier and longer vehicles will consist of more tandem and tridem axles than single axles, this study focused on the relative impacts of the single, tandem and tridem axles. Three typical pavement structures were investigated here with varied material properties during spring and summer. The analyses were based on layered elastic theory carried out with the aid of ERAPave which gave us an overall estimate of the relative impacts of the different wheel configurations. In general, it was observed that the relative impact is dependent on the thicknesses and material properties of the pavement structure and the subgrade. Weaker subgrade is more affected by the tridem axle followed by tandem and single axle. On the other hand, for thicker and stiffer pavement structure, the tridem axle is more damaging to the subgrade. In certain cases, the single axle showed more impact on the top of the subgrade. The tridem axle showed more vertical deflection in all cases that may induce increased fatigue cracking of the AC layer. The speed of the vehicle also has some impact on the damage. Duration of loading was higher for the tridem axle which has more damage potential. Thus, for the whole vehicle, when there are more tridem axles, the effects may be superposed resulting in greater damage. On the other hand, since tandem and tridem axle configurations have higher load carrying capacity, the number of trips required to carry the same amount of goods will be reduced compared to the single axle. This should compensate for the increased damage to the subgrade and the impact on the life cycle of the pavement. However, this study only represented the relative impacts on some typical structures. The actual damage to the subgrades and the effect on the life span of a pavement structure should be further investigated.