交通意外

• 六(six; intersection)ASSOCIATIVE
• 乂(cross; intersect)PHONETIC

Two diagonal lines crossing like human legs stepping represent intersection and exchange.

• 辶(step; move)RADICAL
• 甬(passage; channel; path)PHONO-SEMANTIC

Following a clear pathway or passageway is the meaning of the character.

• 夕(evening; crescent moon (pictographic))RADICAL
• 卜(divination; fortune-telling)PHONETIC

Evening outside divining fortunes under the moon — that's an external affair.