AUSTIN, Texas (AP) — The Texas Department of Transportation has started mailing refund checks to some tollway drivers who were overbilled or billing was wrongly delayed for months.

A legislative hearing has been scheduled Thursday on tollway tag issues. A proposal in the Texas House would require bills to be sent out within 30 days of when tolls are used. Authorities say some billing issues go back to 2012.

Officials say software-related problems were discovered last summer when TxDOT changed billing companies. About 31,000 drivers who use toll tags have already had credits posted to their accounts after being overcharged.

TxDOT Executive Director Joe Weber, at a news conference Tuesday, said reviews found additional overbillings.

The refund checks that were sent, as of Monday, are to customers who already paid outdated bills.

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