By Public Transportation:
It will take 15-30 minutes from Chiang Mai downtown to Chiang Mai Zoo.
"Rod-Dang" or Red Taxi
In lieu of a local bus service, locals get around the city on songthaew (สองแถว). These covered pick-up trucks have two long bench seats in the back (songthaew means "two rows" in Thai), and travel fixed routes picking up passengers en route who are going the same way. Some can also be hired outright.
The colour of the songthaew indicates its general route or usage. Most common by far are red songthaews (called rod daeng, red truck), which don't follow a specific route and roam the main streets around markets, temples, or the bus/train stations. These are the most convenient to take if you are going somewhere specific. Prices must be negotiated. but expect 20 baht anywhere within the city walls and 40-60 baht outside. Because of the city's somewhat irrational road design, especially inside the old walls, the driver may be forced to take a circuitous route to get to a nearby destination, but it will make no difference in the fare.
Fixed route songthaews congregate around Warorot Market. From Warorot Market, white songthaews travel to the eastern suburban city of Sankampaeng, yellowsongthaews travel to Mae Rim in the north, blue songthaews travel to Sarapee and Lamphun in the south, and green songthaews travel to Mae Jo in the northeast. They all charge a 20 baht flat rate.
From Pratu Chiang Mai Market, songthaews also travel to Hang Dong (20 baht) and San Patong, southwest of Chiang Mai.
To catch a songthaew; approach a waiting driver or flag one down on the street, state your destination and if the driver is going that direction he will nod in agreement and give you a price. Negotiate a lower fare if you wish. The price agreed to should be per person; it's a good idea to confirm this with the driver before you leave. On reaching your destination, ring the buzzer on the roof to tell the driver to stop, or most likely the driver will pull over, wait for you to get out and pay.
Chiang Mai has metered taxis, though it can be difficult to persuade the driver to switch the meter on. If you do prevail, the flag fall is 30 baht for the first 2 km, then 4 baht/km after that. Otherwise you will have resort to bargaining a fare. You cannot generally hail taxis in the street. To book a taxi try:
Chiang Mai Airport Taxi, +66 53 201307 or +66 53 922128. Despite their name, Chiang Mai Taxi will take you anywhere. Good, honest outfit. Call, state your destination and the call centre will give you a quote
Or contact individual drivers via the mobile phone numbers displayed on their vehicles
By tuk-tuk or samlor
Tuk-tuks are a quick, though noisy way to get around. Fares are usually 30-40 baht for a short hop (as of July 2012 it seems that the minimum has gone up to 40 baht for pre-arranged locations) and 50-100 baht for longer distances, depending on the proficiency of your bargaining. As a guide, expect to pay 40 baht from the old city to the riverside and Night Bazaar, 40-50 baht to the railway station, and 80-100 baht to the bus station or airport. Tuk-tuks parked near the bus and train stations will ask you for something like 120-150 baht. Just haggle or walk away to the nearest road and stop a passing tuk-tuk or songthaew there.
According to expats, the highest fee for a tuk-tuk at any time of day or night should be 150 baht for any location in town.
The fee seems to be based on multiples of 20 baht which is the smallest note. It is a good idea to stock up on notes and coins as whenever you offer a note higher than the agreed fee the driver has no change!
A few samlor (three-wheeled bicycles) still cruise the streets and will happily take you to a temple for the same price as a tuk-tuk, though at a considerably quieter and slower pace.
Traffic inside the old city walls is subdued enough to make biking a safe and quick way to get around. Bike rentals are plentiful; rental costs 30-250 baht/day depending on the bike quality.
By motorbike or motorcycle
A motorbike is a convenient and cheap way to get around town or reach the outlying sights. There are an abundance of nearly indistinguishable rental outfits in town, and most guest houses can arrange rentals. Automatic 110cc and 125cc bikes capable of carrying two people are the easiest to jump on and ride away with if you don't have riding experience, but off-road bikes and larger street bikes are also an option. A valid international drivers licence isn't required to rent.
Motorbikes run about 150 baht/day for a 110cc motorbike and 150+ baht/day for a Honda Wave 125; supplied with helmets and a security chain. If you rent longer term, e.g., by the month, those rates can be as low as 2,400 to 2,700 baht per month, averaging 80-90 baht per day. Several dealers will agree to these rates. Currently a Honda PCX rents for 350-500 baht per day in the city centre. Monthly rates may lower the daily average.
Larger machines cost 700 baht/day for a V-twin chopper or larger sport-bike. Expect discounts when renting for a week, month, or longer.
Rentals will require a deposit (generally prudent opinion would say that while many ask for a passport you should under no circumstances leave your passport [with anyone] as collateral). It is recommended that you use your discretion to make this assessment as reputable vendors will cause no problems leaving the passport for a month each time. Remember that if you want to leave the country you will need the passport; and that you must ALWAYS carry a photocopy of the passport and visa/entry stamp pages. In this case an additional photo ID isn't a bad idea. Most shops will accept a photocopy with a cash deposit of around 3,000-5,000 baht. This is a much better alternative. While the petrol/gas tank may be full on pick-up, it is not uncommon for shops to deliver a bike with just enough fuel to go make it to a service station. In any case, return the bike with as much or more fuel than received to avoid any penalties. Also check out the relative mechanical merit of the bike being offered. Focus especially on the brakes, the degree of "pull" needed for the handlebar lever, and the travel needed for the foot brake. Check that indicators and headlights work properly, and the tires are reasonably OK.
Some rental agreements claim to insure you but generally only cover the bike for theft or damage. Don't expect much in the way of compensation if something bad such as an accident occurs. Regardless of who is at fault, assume that you will be considered the guilty party.
The police frequently fine riders (including passengers) 500 baht (some officers will allow you to pay 100 or 200 baht on the spot "to avoid paperwork and travelling to the station, etc.") for not wearing a helmet, plus you usually have to go to the police station the next day to collect your licence.
Transportation Information from http://wikitravel.org/en/Chiang_Mai