Speed　reduction　markings　(SRMs),　which　are　widely　used　on　highways　and　urban　roads　in　China,　are　designed　to　inform　drivers　of　the　upcoming　road　conditions　and　thus　encourage　them　to　reduce　travel　speed.　The　objective　of　this　paper　is　to　test　the　effectiveness　of　SRMs　on　drivers’　operating　performance　and　decision　to　decelerate　in　downhill　segments　on　urban　roads.　Data　of　gas　and　brake　pedal　use　was　collected　in　a　driving　simulator　experiment,　and　a　subjective　questionnaire　survey　was　conducted.　Two　indicators—the　operating　frequency　and　operating　power—were　proposed　to　evaluate　drivers’　operating　performance　due　to　SRMs.　Results　of　the　subjective　questionnaire　study　showed　that　the　majority　of　subjects　were　affected　by　SRMs　while　driving　through　downhill　segments　with　distinct　roadway　grades　(3%,　2%,　1.5%　and　1%　in　experimental　scenarios).　In　terms　of　the　operating　frequency,　the　results　of　the　analysis　of　variance　with　repeated　measures　(rANOVA)　and　the　contrast　analysis　(S-N-K　method)　showed　that　transverse　speed　reduction　markings　(TSRMs)　were　significantly　effective　in　influencing　drivers’　frequency　of　letting　off　the　gas　pedal　when　roadway　grades　of　downhill　segments　were　3%,　2%,　and　1.5%　(p＜0.05),　while　longitudinal　speed　reduction　markings　(LSRMs)　had　little　effects;　both　types　of　SRMs　are　effective　in　increasing　the　frequency　of　pressing　the　brake　pedal　in　all　four　downhill　segments.　For　the　operating　power,　the　gas　pedal　power　was　significantly　affected　by　TSRMs　in　all　four　roadway　scenarios;　TSRMs　also　tended　to　increase　the　brake　pedal　power　when　the　roadway　grades　were　2%　and　1.5%,　while　both　types　of　SRMs　had　similar　effects　in　road　sections　with　roadway　grades　of　3%.　©　2021,　Association　of　American　Publishers.　All　rights　reserved.