The Regional Transportation District might experiment with a flat fare, like on the New York City subway system – but only on its newest rail line.

The Denver Post reports that an RTD committee will consider a $3 ride for the entirety of the N Line, which will cover 13 miles from Union Station to Northglenn and will open sometime next year.

A spokeswoman said that the agency is exploring “the relationship between fares and ridership.”

Many transit systems, including RTD, use distance-based fares, with geographic zones that determine how much a rider’s ticket costs. By eliminating the differential fares on the N-Line, RTD would lose an estimated $180,000 over six months.

The lowest-cost ticket now on the RTD system is $3 and the highest, $10.50, applies to trips from Denver International Airport to Union Station on the A Line.

The Washington, D.C.-based Cato Institute found that transit ridership in every state, with the exception of Washington, decreased over the past four years. RTD’s fell from 103 million riders in 2015 to approximately 98 million last year.

Transit systems seek to avoid a “death spiral,” where lower ridership leads to loss of revenue, which results in either service cuts or higher fares – or both. Those in turn deter others from riding, which continues the cycle.