By Greg Argos

PHILADELPHIA (CBS) — If your daily commute includes driving across the Delaware River, you can get a discount on your drive, starting today.

The Delaware River Port Authority is giving an $18 credit to drivers who commute across any of its four bridges at least 18 times a month.

The only catch is you need to have an E-Zpass from New Jersey.

Drivers must sign up for the discount.

The DRPA’s four bridges connecting Pennsylvania and New Jersey are the Ben Franklin Bridge, Walt Whitman Bridge, Commodore Barry Bridge and the Betsy Ross Bridge.