SEATTLE, WA - A new report says that Sound Transit is relying on a 27-year-old formula to calculate car tab fee increases - a formula that was never meant to reflect a car's market value.

In calculating how much car tab fees will increase this year, Sound Transit is using a formula that was created by the state Legislature in 1990 back when the state assessed a tax on cars, according to a new report in the Seattle Times. That formula differs greatly from values reflected in consumer guides like Kelley Blue Book. Last November, more than half of voters in King, Snohomish, and Pierce counties approved Sound Transit 3 (ST3), which will bring new light rail and bus lines to the Puget Sound region from Tacoma to Everett. Several new taxes were included in ST3 to fund those improvements. One was a 0.8 percent car tab fee increase.

In mid-February, reports began to surface of sky-high car tab fee bills. One man, a Tesla owner, saw his renewal fee shoot up to $1,500. The new Sound Transit tax increase will be reflected in car tab renewals after March 1. State Department of Licensing spokesman Brad Benfield told the Times that the formula is not intended to be an assessment of market value. The DOL collects the car tab fees for Sound Transit.

"It was designed to be an easy way to collect what's essentially a property tax on a vehicle. They wanted to make sure that people who had similar cars paid the same tax," he told the Times. A Sound Transit spokesman told the Times that 80 percent of drivers will see an increase of $200 or less.