Many　diagrammatic　guide　signs　in　China　have　become　much　more　complex　and　more　difficult　to　read　than　those　in　other　countries.　Furthermore,　there　are　few　regulations　or　studies　regarding　diagrammatic　guide　signs　in　China.　A　driving　simulator　experiment　was　conducted　to　analyze　the　influence　of　five　typical　diagrammatic　guide　signs　with　different　complexities　on　driving　behavior　and　to　evaluate　their　comprehensive　guidance　effectiveness　via　the　Technique　for　Order　of　Preference　by　Similarity　to　Ideal　Solution.　The　rANOVA　results　indicated　that　different　diagrammatic　guide　signs　have　significantly　different　impacts　on　driving　behavior.　A　higher　complexity　of　the　diagrammatic　guide　signs　negatively　impacted　the　subjective　perception,　operating　status　and　maneuvering　behavior.　With　increasing　diagrammatic　guide　sign　complexity,　the　gas　pedal　power　significantly　decreased　at　distances　of　150-200　m　and　50-100　m　prior　to　the　signs,　the　deceleration　rapidly　increased　150-200　m　prior　to　the　signs,　the　standard　deviation　of　deceleration　increased　100-150　m　prior　to　the　signs,　the　standard　deviation　of　speed　increased　50-100　m　prior　to　the　signs,　and　the　speed　decreased　and　driving　time　increased　0-50　m　prior　to　the　signs.　Eight　indicators　were　used　to　synthetically　evaluate　the　comprehensive　guidance　effectiveness　of　the　five　types　of　diagrammatic　guide　signs.　The　final　ranking　(from　best　to　worst)　of　the　five　diagrammatic　guide　signs　with　regard　to　their　effectiveness　was　obtained.　On　the　whole,　a　negative　correlation　relationship　exists　between　the　complexity　and　the　comprehensive　guidance　effectiveness　of　the　five　types　of　diagrammatic　guide　signs.　This　relationship　should　be　taken　into　account　when　designing　new　diagrammatic　guide　signs　and　optimizing　complex　diagrammatic　guide　signs　in　the　future.