Drivers are courteous on the island: whenever a car has to pull out of a tight spot into traffic, someone will let them in. Whenever there is a traffic jam at an intersection, traffic will flow somehow, because drivers cooperate. The island's administration has experimented with traffic lights - and there is still one up and running in Philipsburg - but overall, lights were a mistake here: friendly driving is more efficient than over-regulating it. Since the light at the intersection on Cole Bay disappeared years ago, the traffic situation has improved.
For our American visitors, a few traffic rules should be explained. St. Maarten/St. Martin follows continental European laws and signs. We drive on the right side of the road, like in the US and Canada. An important rule: traffic coming from the right has the right-of-way! Because this is the 'default' rule, there are usually no street signs on intersections. Only if the default rule is not valid, the right-of-way is regulated with signs. Drivers on the French side stick to this system much more strictly and assume you know.
Also: Watch out for no-parking zones in Philipsburg and at the Airport. The local towing companies behave like sharks (as members of this industry do anywhere in the world) and are just waiting to take your rental car. As a matter of fact, they seem to target rental cars. The fees for picking up the vehicle at the towing companies lot are between $50 to $60.