You can't drive heavy rigid (HR) vehicles without a relevant licence. Typically, you need some training before you apply for one. In some cases, you may need to take a theory test as part of your training to meet eligibility criteria.
When can you skip a theory test and when do you have to take one?
When You Don't Need a Theory Test
While HR licensing may vary between states, you usually have to prove that you understand how to drive heavy vehicles on a theoretical level. You may not have to take a theory test if you can show previous training or experience. For example, you may get a pass on the test if you hold a similar class of licence, such as one that qualifies you to drive medium rigid vehicles. Also, if you've taken an accredited HR training course then your state may let you skip the theory test.
If you've had specific training, you'll have covered relevant driving theory during the course. So, if you pass the course, the understanding is that you have effectively passed a theory test already and don't need to take another one.
When You Need a Theory Test
You'll usually only get a training pass on the HR theory test if you use a company that is approved by your state. These companies usually need to be Registered Training Organisations (RTOs). If you use a non-accredited company, you'll probably have to take the test even though you've had training.
In some cases, people learn to drive HR vehicles without formal training from a company. For example, you can get training from someone else who holds this kind of licence. If you take this route, you will have to take a theory test at some point during your licence application. If you aren't getting formal training, you need to prove that you have the right levels of knowledge to drive this size of vehicle.
To find out about HR licensing regulations in your state, talk to local training companies. They can tell you exactly what you need to do to get a licence.
Bear in mind that formal training may speed up your licence application and approval. As well as making sure you have the right HR knowledge and skills, auto heavy rigid vehicle training providers also administer the practical driving tests you must pass to get a licence. If you don't use a training company, you'll have to organise and pay for this test yourself.