Traffic　conflict　commonly　occurs　in　intersections　with　offset　lane　lines　because　of　mismatched　choices　of　entrance　and　exit　lanes.　This　conflict　drives　down　overall　traffic　efficiency　and　can　cause　crashes.　At　such　intersections,　the　driver＇s　lane　choice　behavior　seriously　affects　the　traffic　system.　The　theory　of　planned　behavior　(TPB)　was　used　in　this　study　to　excavate　the　impact　mechanism　of　drive-by-lane　behavior　at　offset　intersections.　A　scale　incorporating　TPB　constructs　and　additional　variables　(risk　perception　[RP],　traffic　environment　[TE],　optimization　measures　[OM],　and　driving　style　[DS])　was　developed　to　collect　empirical　data　with　557　valid　samples　in　China.　A　structural　equation　model　of　drivers＇　drive-by-lane　behavior　was　established　to　explore　the　causal　relationship　between　behavior　and　influencing　factors,　as　well　as　the　interrelationships　between　TPB　variables.　TE,　behavior　intention　(BI),　subjective　norms　(SN),　and　RP　show　the　most　significant　effects　on　drive-by-lane　behavior.　DS,　perceived　behavior　control,　attitude　(ATT),　and　OM　have　little　impact　on　drive-by-lane　behavior.　BI,　TE,　RP,　and　DS　have　significant,　direct　effects　on　drive-by-lane　behavior.　The　TE,　OM,　and　DS　variables　significantly　affect　drive-by-lane　behavior　through　mediators.　RP,　BI,　and　ATT　mediate　the　influence　of　other　variables　as　well　as　affecting　drive-by-lane　behavior.　We　put　forward　suggestions　to　improve　driving　behavior　at　offset　intersections　including　changing　external　factors,　education,　and　training.　The　direct　and　indirect　relationships　between　the　influencing　factors　and　drive-by-lane　behavior　are　discussed　in　this　paper　to　provide　technical　and　reference　support　for　future　research　on　managing　irregular　urban　traffic　intersections.