A common problem faced by carriers in Less-Than-Truckload transportation is the design of their service network. Given a set of demands to be transported to a set of terminals, a carrier wants to design service routes for his trucks as efficiently as possible. The profitability of the designed service routs depends on the paths chosen to move the freight (line-haul), the back-haul and truck repositioning decisions. A mixed integer path-based formulation is presented to jointly solve the truck scheduling, load planning, and truck repositioning problems in carrier’s operational time-space network. The efficacy of the proposed model is evaluated by a set of test problems solved by solver CPLEX. The solved problems show a significant cost saving resulted from effective freight consolidation, optimal truck schedule and load plans