Speeding,　the　most　frequent　traffic　offense,　is　a　key　contributor　to　road　crashes.　This　study　ex-　plores　the　psychological　factors　affecting　drivers＇　speeding　behavior　(exceeding　the　posted　speed　limit　by　more　than　10%)　based　on　the　extended　theory　of　planned　behavior　(TPB).　The　scale　incorporating　TPB　constructs　and　additional　variables　(Type　A　personality,　risk　perception,　and　driving　habit)　was　developed　to　collect　empirical　data,　and　945　valid　samples　were　obtained.　The　reliability　and　validity　of　the　developed　scales　were　verified,　and　a　structural　equation　model　of　drivers＇　speeding　behavior　was　established　to　explore　the　causal　relationship　between　speeding　behavior　and　psychological　characteristics　and　the　interrelationships　between　TPB　variables　(speeding　intention,　attitude,　subjective　norm,　and　perceived　behavioral　control),　explicit　cognition　predictors　(risk　perception　and　Type　A　personality)　and　implicit　habitual　factors　(driving　habit).　The　results　showed　that　speeding　intention　and　driving　habit　positively　correlated　with　self-reported　speeding　behavior.　In　addition,　attitude　and　risk　perception　positively　corre-　lated　with　speeding　intention.　Although　Type　A　personality　trait　had　no　significant　effects　on　speeding　behaviors,　it　had　significant　effects　on　attitude　and　risk　perception.　In　addition,　the　results　of　the　mediation　analysis　demonstrated　that　speeding　intention,　driving　habit,　and　attitude　toward　speeding　are　the　most　influential　factors.　Attitude　and　risk　perception　have　a　significant　indirect　effect　on　speeding　behavior　mediated　by　speeding　intention.　Drivers＇　attitudes,　driving　habits,　and　risk　perception　played　a　mediating　role　in　the　relationships　between　Type　A　per-　sonality　traits　and　speeding　behavior.　The　findings　yield　insights　into　useful　information　and　directions　for　designing　road　safety　interventions,　developing　driver　education　and　training　programs,　and　strengthening　social　messaging　aimed　at　the　general　public.