I just noticed an article that starting on Dec. 30, 2016, The I-65 Bridge over the Ohio River in Louisville will become a toll bridge. The toll will be transponder/license plate based system - and it will be a part of the EZ-Pass system. Tolls will be $2 for cars with an EZ-Pass or $4 for those without (billed to the registered owner of the license plate).
The same toll will be in place for the brand new I-265 Bridge that will complete the freeway loop around the Northeast side of Louisville, that bridge is scheduled to open in the coming days.
The I-64 Bridge that crosses the Ohio River on the Northwest side of Louisville will remain toll free, but that does add 8-10 miles to the drive, compared to driving straight through on I-65. The Clark Memorial Bridge (US-31) that also crosses the river in Downtown Louisville will also remain toll free, and adds little distance compared to I-65, but does require getting off and back on the freeway.