Unless you're planning on staying at your hotel for the duration of your stay, you'll definitely want to rent a car.  If you like the feel of the sun on your head, and don't mind the occasional rainstorm, get yourself a convertible. It will probably rain at least once while you are here, but it is usually a quick, warm shower. In can pour, especially in winter months on the windward side of the island. Traffic can get very bad at times especially if there is an accident. Patience is the key. Please do not argue with a cane haul truck when they cross either Haleakala Highway or Mokulele Highway. The image below is of two cane haul trucks crossing Haleakala Hwy - the near one is empty and the far one is full.

Two cane haul trucks passing - one full one empty

Local Style tip --> Learning the local shaka hand sign (fold first thru ring finger down, stick out thumb and little finger, then pivot it back and forth) as a thank you will endear you to all locals when you pull over, or ask to merge, etc. Just use it sincerely. Either side of your hand is acceptible. Image here - http://www.shakatime.com/media/The_Sh... - to be clear.

Pedestrian Crosswalks

The crosswalks are white striped additions to pavement; they are also marked along the side of the road with the yellow diamond sign. Stop for people waiting to cross. Know that this is not a state where the pedestrian has the right of way, and not everyone visiting knows to watch out for crosswalks and pedestrian traffic.

Car Security Tip

Don’t leave any valuables in your car and put any travel information you may have in the trunk. Some say to leave your car unlocked, some say lock it up. Use your own discretion and common sense.  

Road to Hana tips

If you’re considering making the famous drive to Hana, keep in mind that it takes a LONG (6-8 hours, including stops to experience the waterfalls), time to get to Hana and an equally long time to get back, or to drive all the way around Haleakala!  If you get carsick, you may want to consider skipping this, although the drive is beautiful and lush. 

Another consideration on the Road to Hana is that most of the bridges are one lane - it is a give and take kind of flow. If there is more than one car waiting, alternate driving over the bridge. Watch for the lines on the road for clues where to stop before the bridges. Also, note that if the yellow center line is gone, the road is officially too narrow to carry two cars. 

More on Road to Hana

Waterfall, road to Hana  

The above photo is of Wailua Falls, one of many lovely waterfalls on the road to Hana. Another option is just going half way down the road to Hana - you won’t see the pools, but you will see many lovely waterfalls and have time to do a bit of hiking near Keanae.

By the time you get all the way to Hana - you have two options - driving the same way back, or driving all the way around Haleakala. Both options are long drives. Read your rental car contract very carefully. Some companies specifically forbid a drive around the southern flank of Haleakala through Kaupo and Kanaio. Leave EARLY in the morning (aim to leave Kahului by 8 am) and realize that you will most likely be following a long line of cars - all going slow and looking at the beauty of Maui also - so if you can’t stand driving slowly on curving roads - just skip this aspect of seeing Maui.

The whole idea of Maui is to slow down the pace of your life - so relax and enjoy it. While seeing Hana's lush sights from a convertible is breathtaking, be aware that the Maui sun is more intense than what you're used to on the mainland. Maui is closer to the equator - 21 degrees North Latitude -  and your regular sunblock regime won't cut it. A bad sunburn can ruin your vacation, even in a place as perfect as Maui. So don't feel bad if you get "stuck" with a regular car. You'll be less likely to burn, and that air conditioning feels mighty good after a long, sweaty hike. You can also take a swimsuit and change for a dip in the ocean to cool off after that hike.