(Chiang Mai)

In Chiang Mai there are no offical buses except to travel to other provencies which is provided
by Bus companies.  To get around Chiang Mai town you must use a Songthaew, Tuk Tuk or a
Taxi.  A Songthaew is a modified Pick Up truck with 2 rows of seats in the back (see pictures)

To hail one, just extend your arm in a downward motion. He will stop.  You tell him where you
want to go.  If he is going your way he will nod yes, if not he will nod his head no.  

This is easier said than done as about 50% of the Songthaew drivers do not speak English, do
not read or write Thai and cannot read a map.  However, they do know the names (in English)
of the most popular destinations.  So, the card or map  the Hotel gave you to show the
Songthaew driver probably won't do any good.  
If you run into this problem and you have a
Business Card of where you want to go, call the establishment and have them give
directions to the Driver
.  A higher percentage of Tuk Tuk and Taxi drivers can understand
English better.

The Normal price to ride a Songthaew is 20 Baht within Chiang Mai town.  For longer trips or
out of the way trips, the price can be negotated.
The color of the songthaew indicates its general route or usage.

Red Songthaews   are the most common by far (hence the alternative rod
daeng, "Red Car" name), which roam the main streets in the city itself. Warorot
Market (by the Ping River) is the most common terminal for Songthaews that
travel along fixed routes.

White Songthaews travel to the eastern suburban city of Sankampaeng,

Yellow Songthaews travel to Mae Rim in the north and Hong Dong

Blue Songthaews travel to Sarapee and Lamphun in the south, and

Green Songthaews travel to Mae Jo in the north-east. The flat rate cost along
these fixed routes is 20 baht. From Pratu Chiang Mai market, Songthaews also
travel to Hang Dong (20 baht) and San Patong, south-west of Chiang Mai.

You may see songthaews out on the highways in the countryside, travelling to
and from small towns and villages. It is probably not proper for them to do this (as
such travel is supposed to be done by bus companies), but in Thailand people
will find a way to make some extra money.
Don's Life In Thailand  (Chiang Mai)