OLYMPIA, Wash. (AP) — A gas tax hike is part of the state House Democrats’ transportation plan.

Democratic leaders have unveiled a 16-year, $25.8 billion transportation package that includes an 18-cent increase in the gas tax and a new fee on carbon emissions.

The Everett Herald reports that supporters say the new revenue is needed to cover the cost of projects like the replacement of the I-5 bridge over the Columbia River and removal of state-owned culverts that are blocking fish passage.

Under the proposal, $17.6 billion would come largely from the gas tax increase.

It would be imposed over the next two years and indexed for inflation going forward.