Know the Roads
You can wing a lot of things while you are on vacation, but two things you don't want to wing are your transportation and knowing the roads. If you plan on renting a vehicle, it will be worth your time to plan things out. With a little planning you can avoid wasting your precious vacation time lost, in rush hour traffic, or waiting in lines for car rentals.
Pedestrian safety. It doesn't matter if you are walking or driving, pedestrial safety should be your number one priority when on the streets. Many areas in Hawai'i, like Waikiki, are very confined and when mixed with a bunch of people unfamiliar with the area and driving unfamiliar vehicles (tourists), an extra level of awareness is necessary. Hawai'i has strict pedestrian safety laws to protect people walking on the streets. But the legal protection of 'right-of-way' given pedestrians should not be taken for granted. Always check for bikes, cars, etc. before stepping into any crosswalk. When crossing a street, stay aware and look for traffic, even on one way roads. As soon as your step into the crosswalk, your next thought should be getting out of the crosswalk. For drivers, slow down when you approach a pedestrian crossing area and be on the lookout. Make eye contact and confirm the mutual respect between driver and pedestrian. Drivers and pedestrians must take equal responsibility. If you are crossing where there is a signal, do not cross after the signal has started flashing red, you will hold up traffic. If you are already in the crosswalk when the signal starts flashing red, quickly continue across the road. Jay-walking will get you busted, so avoid it.
Avoid rush hour traffic. On weekdays avoid driving into town in the morning (6 a.m. to 9 a.m.), and out of town in the afternoon (3 p.m. to 7 p.m.). The weekend traffic is pretty stuffy from late morning to early evening.
Book your car rental ahead of time. Avoid long lines, poor selection of vehicles, and the possibility that the lot runs out. Book your car rental in advance, either before you get here, or locally a couple days before you need it.
North shore traffic. The large winter swells that hit the north shore draw thousands of people to the beaches. This can gridlock traffic for local residents, surfers, and tourists. Even if you get up north in the wee morning hours, you will still be shocked by traffic and the number of people already there. You will probably make it to Haleiwa and the beach parks nearby, but making it to see world-famous Pipeline, Waimea Bay and Sunset Beach in a car is sometimes not achievable. A simple solution to the traffic is using a bicycle. Many people park closer to Haleiwa and bike to the surf spots. Check the surf report and ask around at the surf shops about swells. If there is a big swell, you might want to plan another activity.