The　mixed　driving　of　human-driven　vehicles　(HVs)　and　autonomous　vehicles　(AVs)　is　an　inevi-table　stage　of　future　traffic　developments.　As　HV　drivers　have　different　trust　levels　toward　AVs,　interactions　between　these　two　vehicle　types　will　lead　to　discrepant　characteristics　in　HV　driving　behaviors,　which　will　impact　the　traffic　flow　state　of　expressways.　However,　few　studies　have　considered　this.　Based　on　questionnaire　data,　this　paper　analyzes　the　changing　features　of　the　trust　level　and　its　influence　on　driving　behaviors.　The　quantitative　model　for　the　trust　level　is　constructed　using　the　fuzzy　logic　approach.　On　this　basis,　classical　cellular　automaton　models　are　improved　to　reflect　the　features　of　human-machine　mixed　traffic　flow.　Finally,　correlations　be-tween　the　trust　level　and　the　influencing　factors　are　analyzed,　and　the　impact　of　the　trust　level　on　traffic　flow　operations　is　described　in　terms　of　both　efficiency　and　safety.　The　questionnaire　re-sults　reveal　that　the　influence　of　the　trust　level　on　driving　behaviors　is　universal.　The　trust　level　varies　with　personal　and　contextual　attributes.　The　simulation　results　show　that　traffic　density　and　road　congestion　greatly　influence　the　trust　level.　However,　the　trust　level　is　not　sensitive　to　changes　in　the　penetration　rate　of　AVs.　Interactions　between　these　two　vehicle　types　are　stronger　when　the　penetration　rate　approaches　50%.　The　efficiency　and　safety　of　traffic　flow　operations　under　each　condition　decrease　by　different　magnitudes　from　the　influence　of　the　trust　level.