RiverLink is giving drivers a chance to lower outstanding toll bills and waive late fees.To cash in on the savings, drivers must sign up for an online prepaid RiverLink account before getting a fourth late notice in the mail.Tolls are issued to drivers who cross the Lincoln, Kennedy or Lewis and Clark bridges over the Ohio River. It's $2 per trip for those with a transponder and $4 for those without one. Late fees are issued once a month for up to four months.RiverLink spokeswoman Mindy Peterson says the new offer could turn a three-month-old $38 bill, into a $4 bill."This is an offer that was available before, but you had to pick up the phone and talk to customer service," Peterson said. "Not everyone wants to talk to customer service. This makes it as easy as possible."As of last December, 63 percent of drivers who crossed the bridges had transponders and prepaid accounts.Since the online campaign launched in February, more than 1,000 drivers have already signed up, saving $30,000. To sign up online, click here.