How does a CityLink pass work?
A pass is a convenient option if you only use CityLink occasionally.
You can buy a pass before you travel or if you've already travelled, you can buy a pass within 3 days of your trip. For Weekend Passes, you have until midnight on the Tuesday after the weekend on which you travelled.
There's no need to display a pass in your car, but you may want to keep the receipt for your records.