For newcomers, finding out about the traffic is a very complex thing indeed. So for your convenience, I have collected some of the rules of traffic in Phnom Penh. This will hopefully give you an idea about how to act in traffic (hint: carefully).
Indicating to the left/right: Someone turned on their indicator by mistake and haven’t discovered it yet.
Honking your horn: Can have several meanings, including: “I go straight”, “I turn left”, “I turn right”, “I stop”, “I speed up”, “You should move”, “You should stay”, “I have a new car” and “Don’t you honk your horn at me”.
Driving side: Right-side-driving seems to be the most popular, with almost 50% choosing to drive here. Middle-of-the-road is second most popular, with about 30% of the traffic, and Left-side-driving only sees about 20% of the traffic. Left side and middle-of-road seem to be gaining popularity, though no official polls are known to this author.
Max load: An ongoing competition to see who can put most people and stuff on any vehicle.
Zebra crossing: If you are an actual zebra, traffic might stop for you here. Purpose of these drawings are hitero unknown, though, as the number of zebras in Phnom Penh is rather low.
No u-turn: This indicates the place best suited for a u-turn and people queue up to do one here.
Full stop: This sign decorates many streets. Its origin and purpose has not yet been discovered, but it is assumed to be religious.
Speed limit signs: These indicate 2-digit numbers on streets where your max speed is 5 km/h. This explains to drivers that it would be safe to go this speed if it weren’t for all those other guys blocking your way, which seems to make everyone happy to know.
Traffic lights: A festive decoration in the main streets. Red means “go if you can”, as do yellow and green.
Drivers license: A souvenir sold to expats and other long-term visitors in Cambodia. A very small group of locals have been known to purhcase this souvenir too.
Sidewalks: A convenient location to park motorbikes and do street vendoring. Walking here is frowned upon, as it may inconvenience someone trying to park a motorbike.
Tuktuk: Both a means of transport, and the most popular way to greet westerners visiting the Land of Wonder.
But seriously, though
When you do walk in Phnom Penh traffic, walk slowly. In Bangkok it is necessary to run across streets to get over while the light is green. Here, if you don’t walk slowly, you will be hit. Walk a few steps further over the road when you see your chance to do so. Walk as close to the sidewalk as you can come, but not on the pedestrian street itself (except on Riverside). Oh, and stay alert.
If you choose to drive a motorbike, go with the flow. If it is “your turn” to go, even if the light is red, people will get annoyed at you for standing still. You should always wear a helmet and have indicators and lights working on your bike – but this is more about getting pulled over than for actual traffic purposes.
Bicycles seem to go by pretty much the same rules as motorbikes, albeit a bit more carefully. There are no rules about helmets on bicycles,
If you choose to drive a car – best of luck to you.