Platooning　is　the　application　of　autonomous　driving　technology　to　provide　a　freight　transportation　solution.　It　can　improve　the　efficiency　of　freight　transportation,　save　energy　and　reduce　consumption,　which　are　the　major　concerns　of　freight　transportation.　Configuration　strategies　are　sets　of　rules　for　vehicles　joining　a　platoon.　Two　types　of　configuration　strategies　are　proposed　in　this　paper,　namely　fixed　platoon　configuration　strategies　(Fixed-PCS)　and　flexible　platoon　configuration　strategies　(Flexible-PCS).　In　order　to　verify　the　impact　of　these　strategies　on　freight　efficiency　and　energy　reductions,　an　energy　consumption　model　is　designed　and　performed.　A　discussion　about　the　maximum　platoon　length　and　a　design　of　platoon　configuration　strategies　in　connected　and　autonomous　driving　scenarios　are　presented.　For　freight　vehicles,　an　agent-based　simulation　model　is　established,　in　which　the　efficiency　and　consumption　evaluation　indicators　are　used　to　measure　the　platooning　effect　under　different　traffic　densities.　The　results　show　that　in　low-density　traffic　flow,　the　application　of　Flexible-PCS　can　improve　the　average　speed　on　freeway　in　addition　to　reducing　the　average　number　of　lane　changes.　The　relationship　between　platoon　length　and　energy　consumption　at　different　traffic　flow　densities　are　plotted,　and　recommendations　on　the　optimal　platoon　lengths　under　different　traffic　flow　densities　are　proposed.　©　2023　Elsevier　B.V.