I used to hear the "call of nature" excuse a lot when I was a cop. Some folks think that offering up a somewhat embarrassing personal excuse is going to get them out of a ticket. Most of the time, they were lying, IMO. Of course, I hated writing tickets and used nearly all my traffic stops as excuses to check for warrants, anyway, so I generally just issued warnings.
If someone was driving so horribly they were endangering others, I took 'em to jail on a reckless driving charge.
There were plenty of 'traffic' cops in our department to take care of ticket writing and revenue generation. I was busy enough putting people in jail for DWI, robbery, burglary, assault, and various other 'real' crimes.
Traffic enforcement was just a good excuse for me to execute some felony warrants during the down times between those calls.