PROVIDENCE, R.I. (AP) — An effort is underway to replace Rhode Island’s distinctive ‘wave’ license plates and more than double the cost of the new ones.

The state Senate on Tuesday approved a measure to start replacing them later this year by a 27-8 margin.

The bill would change the price of a license plate from $6, set 20 years ago, to $15.

Sen. Louis DiPalma, one of the bill’s supporters, says some plates still on the road are so old and worn they are difficult to read. The Middletown Democrat also estimates about 25,000 vehicles are using invalid plates, probably because they are unregistered, uninsured or uninspected.

Some senators opposed the price hike, saying many people could not afford it, especially if they have multiple vehicles.

There is no new design yet.