An NBC 5 investigation has discovered that money from drivers who overpay on ZipCash bills is deposited into what the NTTA calls the Overpayment Account -- not refunded or credited toward a future trip on a toll road.
The NTTA says there is currently $57,812.42 in the overpayment account.
The account was created in August of 2009. But the NTTA has only provided NBC 5 Investigates with a detailed spreadsheet documenting transactions from May 2010 to Nov. 26, 2012.
Customers who find their names on the list can call the NTTA customer service center at 972-818-NTTA (927-818-6882). The agency says it will credit the money to their account if the customers can provide proper identifying information.
Use this database to find out if you've overpaid.