From the Treo site:
Failing to pay your toll
Once you receive your invoice, you have 30 days to pay your tolls. After 30 days interest will be accrued daily on the outstanding balance at a rate of 19% per year, compounded monthly. Once your balance reaches more than $25 in tolls, your account will be classified as Refuse To Issue (RTI). ICBC will be notified that you are unable to renew your driver's license or car insurance until the toll debt has been paid in full. At this time, additional fees and interest charges may also apply.
Unpaid tolls by out of province users will be subject to collections.