With　the　development　of　autonomous　driving　and　communication　technology,　the　heterogeneous　traffic　flow　by　combining　connected　and　autonomous　vehicles　(CAVs)　and　manually　driven　vehicles　(MVs)　will　appear　on　the　freeway　in　the　near　future.　It　is　expected　that　CAVs　can　improve　the　freeway　capacity　and　reduce　vehicle　exhaust　emissions,　but　sharing　the　same　road　by　CAVs　and　MVs　will　cause　certain　interference　to　CAVs.　In　order　to　reduce　the　negative　influence　of　the　heterogeneous　traffic　flow,　setting　up　CAV　dedicated　lanes　to　separate　CAVs　from　MVs　to　a　certain　extent　is　regarded　as　a　reasonable　solution.　Based　on　the　characteristics　that　MVs　should　be　decelerated　by　a　realistic　amplitude　and　that　the　connected　and　autonomous　vehicle　can　accurately　predict　the　speed　of　its　preceding　and　rear　CAVs　at　the　next　time　step,　a　heterogeneous　traffic　flow　model　was　established.　Based　on　this　model,　we　studied　the　overall　influence　of　different　lane　strategies　on　the　operating　efficiency　of　freeway　traffic　flow　and　vehicle　exhaust　emissions　under　different　densities　with　different　CAV　penetration　rates.,e　results　show　that　setting　up　CAV　dedicated　lanes　with　low　CAV　penetration　rates　will　have　a　negative　impact　on　the　freeway　traffic　flow.　When　the　CAV　penetration　rate　is　40%-60%　and　the　density　is　not　less　than　30　veh/km/lane,　setting　up　one　CAV　dedicated　lane　is　the　best　choice.　When　the　CAV　penetration　rate　exceeds　60%　and　the　density　is　not　less　than　40　veh/km/lane,　setting　up　two　CAV　dedicated　lanes　is　the　best　choice.,e　research　finding　will　assist　in　understanding　the　overall　influence　of　CAV　dedicated　lanes　on　freeway　traffic　flow　and　help　determine　the　optimal　number　of　CAV　dedicated　lanes　under　different　traffic　conditions.