The fate of $30 car tabs in Washington will be decided by the state Supreme Court.
Supreme Court justices announced Wednesday they will hear arguments on Initiative 976 in May and June.
I-976, which caps car tab fees at $30, was approved by voters in November.
A coalition of cities, King County and Garfield County's transit agency sued, saying it would eviscerate funds they need to pay for transit and road maintenance.
The state’s budget office estimates I-976 would eliminate more than $4 billion in tax revenue by 2025.
The coalition claims the initiative is unconstitutional because it violates the single-subject rule, which prevents bills from containing more than one subject and mandates that subject should be expressed in the title. They also called the initiative "a poorly drafted hodge-podge."
A King County Superior Court judge rejected most of the challenge to I-976 in February saying the coalition failed to carry the burden of demonstrating that the measure was unconstitutional on most of their claims.