While in Haiti a rental is a great option, but unfortunately rentals in Haiti are very very expensive.
Avis is usually the best choice, which is by the airport. Memory rent car is also a good choice on Clercine before you reach Tabarre. Using public transportation is definitely not for the average person, you will experience fatigue from the heat and over crowding. And riding public transportation in Port-Au-Prince is not recommended for safety reasons.
If you want to visit the provinces the best option is flying. Tortugair airways is my personal favorite and I highly recommend flying with them. Prices are around $140USD round trip. There's also a new airline called Tropical Airways I used them once In February to go to the Carnival in Cap - Haitien.
Pricing is around $125USD.
There is regular public transportation but also there are many decorated trucks. Yes there's plenty for the eye but not much for the bottom!
Expect as little as a piece of wood to sit on and metal or more wood to support your back. And remember these are just regular trucks that have been decorated, get ready to feel all those bumps.
In the ones like the truck pictured in the main picture for this tip the drivers put really loud music, when I say loud I mean LOUD with lots of bass and lots of noise in it. The passengers just love it!
Actually I would suggest you avoid that kind of transportation as much as you can, I know I do.
Taptaps are trucks that look 'somewhat' nice with all there paitings on the outside. However don't be fooled. They are not the safest thing. The way they work is that you everyone piles in the back cab of the truck. If you're lucky you have a little wood bench to sit on. I saw small 1/4 ton Toyota trucks carrying aproxmiately 15 people. If people could grab on to piece of metal on the truck, they were a passenger, that's basicaly how it worked.....and I thought Toyota's were crap....
Taptaps are brightly painted local transportation. You can't miss these moving art pieces as they lumber by covered in art drawings of Hollywood celebrities and/or patron saints, usually accompanied by a Creole phrase. Typically filled to the brim with passengers and cargo. Personally, I questioned the safety of these and avoided them. Would recommend the same, but it depends on your comfort level.
Craziest thing ever.....I wouldn't plan on renting a car unless you are a daredevil. No traffic laws, lights or sings make it a nutty place to drive. TapTaps aren't the safest things to drive in. If you can afford it, I would encourage hiring a driver or taking a taxi. It's the best way to go...
Beautifull Chicken truck that a lot of team members got to ride in. Not only up the street but about for 45 minutes away!!! My butt was spared!hehehe