At the moment the C-Train costs $1.50 for Adults and $0.90 for children (this is the same cost as for bus-rides). You can buy a ticket from the dispensers at the platforms, or you can buy a book of ten tickets (at a reduced cost), available at a number of convenience stores across the city.
Important: The C-Train operates on a monitored "honor-system". This means that there is no-one to take your ticket, you are expected to have a valid ticket. This is checked periodically by C-Train cops who will demand to see proof of payment should they be checking (and they do it often enough that you probably shouldn't bother trying to dodge them). The fine for riding the C-Train without a valid ticket is currently at $150.
What constitutes a "valid" ticket? If you have bought a ticket from a dispenser, or have a transfer obtained from a bus used to connect to the C-train, you have no problem. However if you have purchased a book of tickets from a convienence store you must validate the ticket before boarding the train. You validate your ticket at one of the ticket dispensers at the platform. Look at the dispenser. In the bottom left-hand corner of the dispenser there is a little slot with an arrow pointing to it, with the caption "validate here". Stick the white edge of your ticket into the slot (white side up) and a time stamp will be written across the top of your ticket, thus validating the ticket. Simply having an unvalidated ticket won't get you out of a ticket.
If you board the C-Train downtown, and just want to ride it downtown, no fare is needed. This is called the "free-fare zone". At the stops at the end of the free-fare zone there is an announcement made telling you that you are leaving the free fare zone and that you must have a valid ticket to continue.
The C-train runs regularly from morning until midnight. It takes a maximum of about 45 minutes to ride from one end of the route to another. Try it, it beats driving in rush-hour traffic.
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