It depends on which method of transport you decide to take. If you take the train it generally takes about 15 minutes to drive from Halls Head to the Train Station (including parking and walking onto the train from the car park). Then it takes approximately 45 minutes by train into the Perth CBD. So you could expect a trip to take around 1 hour. Driving by car is fairly similar in time, unless you are driving in peak hour, then your traveling times can blow out quite a bit.