The Pacific Highway is the major road link between Sydney and Brisbane. Additionally, it passes through a populous area of New South Wales, connecting you with many of the state's major cities and towns. The Pacific Highway is 800 km. long. It is possible to drive up the highway in a single day, but this is a six segment itinerary with several shorter drives and a number of stops in New South Wales cities.
When planning a trip up the Pacific Highway, the major consideration is holidays. The Pacific Highway links several large Australian cities and also passes through major beach holiday areas close to Sydney. Thus traffic is absolutely nightmarish at either end of a holiday period; it's not unheard of for trip times to be four times as long. The worst times to be traveling north are the afternoon and evening of Christmas Eve (or of the day before if Christmas Eve is a Sunday), the afternoon and evening of the day before the Good Friday holiday and the night before and morning of the first day of any long weekend. When traveling south, the end of holiday periods are the peak time. Since Australians take summer holidays in January, you will also want to avoid traveling north on the Friday or Saturday of any weekend in January, and likewise avoid traveling south on Sundays in January.
As the Pacific Highway is a major road passing through a populated area, there's no need to take special precautions as you might when driving through a remote area. It might be a good idea, as with all car trips, to make sure that you have food, water and warm enough clothing so that having to sleep in the car for a night wouldn't be a disaster. However, you wil have ample opportunity to purchase all food and drink along the way.
You can start from either end of the road, or from many points along its length. To the south, Sydney is a major gateway, and to the north Brisbane and the Gold Coast both have many transport options. You can hire a car at either end, shop around for a good one way deal if you need one.
This section of the drive passes starts on the foreshores of Sydney Harbour, passing through the leafy suburbs of the North Shore all the way to the Hawkesbury River in the north. There are freeway sections bypassing the parts from the Harbour Bridge to Chatswood and from Wahroonga to the Hawkesbury if speed is of the essence. The section from Chatswood to Wahroonga cannot be readily bypassed.
The Pacific Highway starts directly on the northern side of the Sydney Harbour Bridge. Stay left over the bridge and take the Pacific Highway exit (you can't access the highway from the tunnel). Immediately you are passing the skyscrapers of North Sydney, the second largest business district in New South Wales.
Upper North Shore to the Central Coast
This section of the drive offers drives through national parks, bushland and small townships and communities. It is easy to stop and take advantage of bushwalking opportunities, coffee shops and views, and beaches.
This section of the road is entirely bypassed by the Sydney to Newcastle Freeway, and is pleasant a quiet driving if you are not in a hurry.
Central Coast to the Hunter Valley
Hunter Valley to Port Macquarie
Port Macquarie to Coffs Harbour
Starting from a junction with the Pacific Highway at Raleigh, midway between Urunga and Coffs Harbour, Waterfall Way travels westward to Armidale. This route has been voted the best tourist drive in NSW and in the top 3 of Australia.
Ballina to the Gold Coast
This section is mostly four-lane highway. A very scenic drive passing through mountains, tunnels and farmland. Highly recommended for sightseers.
The highway is four to eight lane motorway. This section is the busiest road in Queensland and is prone to congestion. Peak hour traffic and accidents can back the highway up for miles. Otherwise, it is the easiest route to Brisbane and has plenty of service stations and shopping centres on the way.
The Pacific Highway was one of Australia's most dangerous roads for accidents and fatalities: over 20 people died on the road every year, and historically it has been the location of some of Australia's worse traffic accidents. Most of the road is now four-lane standard but there are sections between Coffs Harbour and Ballina that are still single-lane. Full duplication is expected to be completed by 2020.
Some sections have several twisty parts of the road where the road narrows and visibility is poor. Trees close to the sides of the roads are unforgiving of any mistakes made at speed. This is especially true on the single-lane sections. You should exercise a great deal of caution, and not let the popularity of the route or its prominent status lull you into mistaking it for a safe drive.