A tax on cargo containers going through Washington ports has been proposed by state senator Mary Margaret Haugen, reports the Tacoma News Tribune.

The levy is expected to raise an estimated US$287 million in the next two-year budget and will be used to help pay for road and rail improvements that shippers say they need, Sen. Haugen said in the report.

The senator, who chairs the Senate Transportation Committee, proposes that a tax of $50 be imposed on a TEU and $100 pr FEU.

Port officials reportedly oppose the tax saying that it would drive shipping to Portland or Vancouver, British Columbia.