There are two very
different types of police checks taking place in the Sukhumvit area of Bangkok. From time to time
you might walk by, or more likely, be a passenger in a vehicle stopped at an
intersection where a police checkpoint has been set up. These
checkpoints may take place deep in some sois (between soi 23 and 33, on soi
16 and on soi 39 seem to be the main spots) but are usually carried out at
the Asoke intersection itself, where traffic coming up from Rama 4 Road
turning left on to Sukhumvit is stopped. It's a favourite late-night
checkpoint spot. Officers target motorbikes, pickup trucks, taxis, any
vehicle with foreign passengers and private vehicles with passengers in
their teens and early 20s. The officers shine torches in to the
vehicle and in some cases may ask occupants to get out.
The cops at these organized checkpoints are professional and
polite.
The other checks carried out in the area are made by
two coppers riding around on a motorbike who ride right up to and stop foreign males. They usually
ask where you're going, where you've been and then make a decision whether
they are going to search you or not. My experience has been that responding
in polite Thai ends it with no mention of a search at all.