Passport or driver's license, in a manner of speaking

ACCIDENT

Think of what these documents might unintentionally cause when things go wrong on the road.

This clue plays on the phrase "by accident," which can mean unintentionally—but here, it’s hinting at the answer itself. A passport or driver’s license is something you carry on your person, and "in a manner of speaking," it’s an ID—sounding like "I.D." or "I, D," which phonetically resembles "accident" when you say it out loud as "I-D-ent." The wordplay relies on the pun between "ID" and how it sounds when stretched into the answer.