Many roads are very narrow despite being two-way roads, which makes it very difficult for large cars to pass another vehicle. Occasionally, I'll see large SUVs or trucks, but this is not common. There are also a few very high-end vehicles, like Porsches, getting around on this island!
Bus transportation is also very popular, with bus stops located throughout the island, and the low cost of this method of travel makes it attractive to many people. Unfortunately, this method can be even slower than travel by car due to the number of stops letting people on and off of the buses.
The island is currently in the process of planning for a light rail system. This will greatly benefit residents as it will greatly ease the traffic burden and permit a more efficient manner of travel.
Lastly, some people travel exclusively by bicycle! Bicycling might difficult for someone who works far from home, but it is definitively the most economical option by far.
I had to purchase a little car, a Nissan March, when I arrived in Mauritius. Buying my car was a confusing and stressful experience! I did not understand the processes for registration, taxes, car insurance, and everything else that comes with car ownership on this island. To top it off, there was a bit of a language barrier at the small dealership where I purchased my car. In this situation, I had to cross my fingers and hope for the best. So far, so good!
Learning to drive in Mauritius was a bit of a learning curve for me! I have only ever driven in countries that drive like we do in the United States, on the right side of the road.