It's the law in Thailand, not mentioned in travel brochures

Police Stop & Searches Around Sukhumvit / Asoke On The Rise

Let’s get authoritarian | Bangkok Post: Post Bag Opinion

Everyone is required to carry identification.  In case of foreigners, the only acceptable identification is the passport.  The few times I have been stopped while driving a motorcycle, a Thais drivers license was sufficient.

Thai law gives the police the authority to stop vehicles and pedestrians and demand identification, ask to see the contents of pockets, and bags.  They can also demand a urine sample.

Drug use in Thailand, especially yaba (methamphetamine) is quite rampant. 
The reasoning for these searches is to apprehend drug users and dealers.  Besides apprehending drug transporters, stopping vehicles also leads to discovery of unregistered vehicles, unlicensed drivers, and stolen vehicles.

The best thing is to be aware of these laws and carry proper identification and follow the police officer's instructions.  Don't give the police a reason to arrest you or 'fine you.'

Urine tests are most prevalent in areas predominant with bars and clubs.
It was about 15 years ago when I had to submit to a urine test.  It was done at a disco, the place was shut down and about 200 people had to submit to a urine test.  I wrote about that before on January 8, 2011 Amazing Thailand: Enjoyable Recollections

Last year I heard of random urine test being done on the Phu Phan highway. 
You can also expect vehicle searches for drugs on highways and streets near Thailand's borders.
Sakon Nakhon

Amazing Thailand: Enjoyable Recollections

Chapter 1

There's nothing more enjoyable on a vacation to Thailand than a random drug test.
I experienced one during my vacations back in the 1990's.
A night at a Bangkok disco with some friends.

Houselights were turned on, announcements in Thai, I didn't understand a word.
I had no idea what was going on, except for the fact that there where dozens of uniformed police standing by the door, and everyone seemed to head toward the exit.

Passport in my hand, I made my way through the crowd to the main exit.
A policeman personally escorted me back to the toilets, handed me a cup, and made sure that I filled it with my own...

My plumbing gets shy when people are watching.
The policeman was earnest and getting impatient.
Finally I was able to perform the required task. Now the fun really started.

Satisfied, the policeman directed me to the end of the line and disappeared.
A few hundred people ahead of me, all holding these shallow, easily crushable paper cups.
The cups weren't much larger than those they serve butter and jam in for breakfast.

With people lining up behind me, I was now in a mob of a few hundred people, all pushing toward a single door exit.

Many people where holding their cups above their heads in order to avoid being bumped into.
It didn't help,  the yellow smelly stuff got spilled all over.  There was a kind of mist in the air.

Empty cups were refilled right on the spot.  Expediency outweighed shyness.
Made no sense to return to the toilet and wind up at the end of the line.

Lot's of kind and understanding people, they had plenty, enough to help out their friends.
The way this stuff was being poured from cup to cup, you'd think we were in a champagne bar.
A Thai ahead of me turned and smiled: "Welcome to Amazing Thailand."
It was one of those fun Thai smiles you hear so much about.

I inched my way toward the door, holding my hand over the cup to avoid spray contamination.
I became a bit worried.
Would any of my prescribed medicine I had taken cause a positive test result?
I didn't follow a friends advice to carry copies of my prescriptions with me. just in case...

I was noticeably nervous while the attendant was performing the litmus test on my contribution.
I was tremendously relieved when my fortune was told: "Negative, you can go."

Those where the early days.  I suspect improvements have been made.  The exchange program has probably been abolished.

Incense, not just for rituals

I use it daily to ward off mosquitos

5:30 AM,  Saturday

Used to consider this kind of temperatures ideal T-Shirt weather.
Nowadays those temperatures make me shiver, especially riding a motorcycle.
I'm getting older.

-----------------------	Saturday	Sunday	Monday	Tuesday	Wednesday
Thai Meteorological	26/11	27/11	28/12	28/11	27/11
Accuweather	29/14	29/15	29/16	29/14	30/14
Weather Underground	27/13	28/15	27/15	26/13	27/12

Been there, Done That: 1960's, Anchorage, 50 mph winds, held my jacket open as a sail.  Fastest trip through town I ever made.

Silly, but cute

Ya gotta stretch before and after excercising