This paper investigates an automated truck transportation problem via lane reservation strategy. The focus of the problem is to design lane reservation based paths for time-efficient transportation. The lane reservation strategy requires to select some existing general-purpose lanes from a transportation network and convert them to automated truck lanes in order to ensure the time-guaranteed transportation. However, such conversion may cause traffic impact such as increase of travel time on adjacent lanes due to the disallowing use of the automated truck lanes by the general-purpose vehicles. Thus, the problem aims at optimally designing the time-efficient truck paths while minimizing the impact on the overall network performance. The considered problem is formulated as an integer linear program and is demonstrated NP-hard. To solve it, an optimal algorithm based on the cut-and-solve method is proposed. Numerical computational results of randomly generated instances show the efficiency of the proposed algorithm compared with a referenced software package CPLEX 12.1.