There are no freeways on the island and 55 mph is that fastest speed limit. Most speed limits are slower than you would expect so watch them close. You will also notice that cars tend to pull out in front of you often. It may seem like they are not giving you enough time to stop safely, but before you cuss and blow your horn, take a look at the speed limit and your speedometer. You are likely driving too fast.
Horns are decidedly uncool on Maui.
Obviously, if you are in a parking lot and someone is backing into you, you need to let them know. But no matter how wrong someone is in traffic, blasting your horn to let them know what you think is frowned upon. You are on vacation and should leave the stress behind. Please do the same. Local police do set up drunk driver checkpoints on a random basis for the safety of everyone on the island.