Driving　under　the　influence　of　alcohol　on　curved　roadway　segments　has　a　higher　risk　than　driving　on　straight　segments.　To　explore　the　effect　of　different　breath　alcohol　concentration　(BrAC)　levels　on　driving　performance　in　roadway　curves,　a　driving　simulation　experiment　was　designed　to　collect　25　participants＇　driving　performance　parameters　(i.e.,　speed　and　lane　position)　under　the　influence　of　4　BrAC　levels　(0.00%,　0.03%,　0.06%　and　0.09%)　on　6　types　of　roadway　curves　(3　radii　x　2　turning　directions).　Driving　performance　data　for　22　participants　were　collected　successfully.　Then　the　average　and　standard　deviation　of　the　two　parameters　were　analyzed,　considering　the　entire　curve　and　different　sections　of　the　curve,　respectively.　The　results　show　that　the　speed　throughout　curves　is　higher　when　drinking　and　driving　than　during　sober　driving.　The　significant　interaction　between　alcohol　and　radius　exists　in　the　middle　and　tangent　segments　after　a　curve　exit,　indicating　that　a　small　radius　can　reduce　speed　at　high　BrAC　levels.　The　significant　impairment　of　alcohol　on　the　stability　of　speed　occurs　mainly　in　the　curve　section　between　the　point　of　curve　(PC)　and　point　of　tangent　(PT),　with　no　impairment　noted　in　tangent　sections.　The　stability　of　speed　is　significantly　worsened　at　higher　BrAC　levels.　Alcohol　and　radius　have　interactive　effects　on　the　standard　deviation　of　speed　in　the　entry　segment　of　curves,　indicating　that　the　small　radius　amplifies　the　instability　of　speed　at　high　BrAC　levels.　For　lateral　movement,　drivers　tend　to　travel　on　the　right　side　of　the　lane　when　drinking　and　driving,　mainly　in　the　approach　and　middle　segments　of　curves.　Higher　BrAC　levels　worsen　the　stability　of　lateral　movement　in　every　segment　of　the　curve,　regardless　of　its　radius　and　turning　direction.　The　results　are　expected　to　provide　reference　for　detecting　the　drinking　and　driving　state.　(C)　2014　Elsevier　Ltd.　All　rights　reserved.