Deterioration models significantly contribute to increasing the efficiency of life-cycle planning for highway assets. Therefore, asset managers strive to maximize the accuracy of such models and intensify the efficacy of the life-cycle plan. Even though nearby assets have been thought to have an impact on each other's conditions, usually, such interrelations have not been considered in previous deterioration models. To this end, in this paper, we focused on investigating the impact of considering nearby assets interrelations on the accuracy of prediction models. Our results show that this consideration resulted in more accurate prediction models in comparison to considering each asset individually.