Freeway　bottleneck　areas　are　prone　to　congestion　and　have　high　accident　risk.　A　variable　speed　limit　provides　technical　support　for　alleviating　congestion　and　improving　traffic　safety　in　such　areas.　The　existing　variable　speed　limit　rules　in　the　related　literature　have　a　single　focus,　and　most　of　them　do　not　give　specific　quantitative　speed　limits.　In　this　study,　a　variable　speed　limit　system　suitable　for　freeway　bottleneck　areas　was　constructed.　Variable　speed　limit　rules　under　different　levels　of　traffic　congestion　and　adverse　weather　conditions　were　designed,　and　the　parameters　for　freeways　were　defined.　Then,　the　VISSIM　microscopic　traffic　simulation　software　was　used　to　build　two　bottleneck　scenarios　of　a　tunnel　area　and　a　merging　area　for　simulation　tests.　The　research　shows　that　in　these　two　scenarios,　reasonable　speed　limits　can　effectively　reduce　roadway　delays　and　improve　the　operational　efficiency　of　bottleneck　areas　in　certain　traffic　flow　ranges　(e.g.,　a　medium　flow　of　around　900　pcu/h/lane).　Unreasonable　speed　limits　in　low　flow　inhibit　freeway　efficiency　more　significantly.　When　congestion　has　already　formed　with　high　flow,　different　speed　limits　have　a　limited　effect　on　efficiency　improvement.　The　research　results　reported　in　this　paper　can　provide　a　theoretical　reference　for　the　design　and　practical　application　of　variable　speed　limit　systems　in　freeway　bottleneck　areas.　This　provides　a　certain　contribution　to　sustainable　traffic　development.