Road numbering in the USA is very logical and the basic rule is that odd-numbered roads generally run North-South and even-numbered roads run East-West. Sometimes this is not obvious when you look at a short section of road but becomes clear when you look at a longer section.
When deciding your route you need to consider whether you to take the quickest, shortest (distance!) or most scenic. They are usually different. Most good maps will mark the scenic routes and you have to consider that the shortest distance my be through very slow, windy and narrow roads whilst the longer distance may be a quicker drive.
Driving on the RHS of the road can be quite daunting at first and it is essential that you concentrate hard for the first few days. It is helpful if you are being driven by someone else for a while before driving yourself as this gets you familiar with being on the RHS of the road even if not in the driving seat. Usually you adapt quickly when you are driving along highways where you do not have to make many manouvres but when you have to make turns etc. you need to keep your wits about you. You will also find that initially, when you start off on a new day of driving, you may slip into your LHS habits unless you concentrate hard so take that extra bit of care when you start out each day. After a week or so you will find it becomes second nature. The most common problem initially is that you will look out of the left side of the car when trying to look in the rear view mirror!
Freeway travel is fast and most drivers routinely exceed the speed limit by 10 to 15 m.p.h. Speed limits vary considerably between states so look out when you cross state borders. Signage is generally very good and exit numbering is excellent in that the numbers refer to the distance from a given point rather than just sequential numbers. This makes it much easier to calculate how far it is to your desired exit and is something which could be usefully adopted in Australia and elsewhere.
Your time of travel will dictate the traffic density but it will often get quite slow and even stationary near large cities, otherwise it is usually significantly higher than most Australians experience. As you get closer to cities the number of lanes may expand to as many as 6 each way with lots of exit and entry ramps. If you are staying on the freeway you can usually find a lane which will take you through the city area with minimum encounters with exiting and entering traffic but be prepared for delays.
In many areas summer is the only time that roadworks can be carried out so you will experience delays from waiting at controlled sections of road. These can be quite long sections and you will often find that when it is your turn to go you will be led through by a works vehicle.
