Democratic lawmakers in Olympia have proposed their own legislative fix to increased car-tab fees, in the form of five separate bills targeting Sound Transit.

The bills are just the latest that have been introduced amidst growing concern over a tax increase put in place after the passage of Sound Transit 3. The tax increase resulted in higher car-tab fees for drivers within the Sound Transit District in King, Pierce, and Snohomish Counties.

In some cases, drivers have said their car-tab fees doubled or even tripled.

Sound Transit 3 was approved by voters in November 2016. It is a 25-year, $54-billion transit package that will expand mass transit and light rail service within the Sound Transit District.

Over the last few weeks, Republicans in the GOP-led Senate have been pushing several bills aimed at Sound Transit reform.

Now, Democrats in the House are have come up with their own version of legislation to address the controversy over car-tab fees.

House Bill 2147, sponsored by Rep. Mike Pellicciotti, D-Federal Way, would change the way that Sound Transit values cars for the purposes of the Motor Vehicle Excuse tax that funds Sound Transit 3. It lays out what lawmakers view as a faster and more fair depreciation schedule for vehicles, with a goal of lowering car-tab fees for taxpayers.

Related: DOL admits some inaccurate MSRP figures used for car-tab taxes

House Bill 2148, sponsored by Rep. Kristine Reeves, D-Federal Way, would allow Sound Transit to offer a rebate of up to 40 percent on car-tab fees for low-income vehicle owners. It would offer a similar rebate of up to 40 percent on ST3 property taxes for low-income homeowners.

House Bill 2149, sponsored by Rep. John Lovick, D-Mill Creek, seeks to provide Sound Transit-related information and accountability directly the taxpayer. It would require the Department of Licensing to send out details on the budget and status of various Sound Transit projects being funded by car-tab fees. The information would be included in the car-tab renewal bills that DOL sends to taxpayers on behalf of Sound Transit.

House Bill 2150, sponsored by Rep. Shelley Kloba, D-Kirkland, also seeks to hold Sound Transit more accountable as it relates to being on time and on budget. The bill would require county auditors to send taxpayers an accountability statement, with updates on the status of Sound Transit projects.

House Bill 2151, sponsored by Rep. Christine Kilduff, D-University Place, would direct transit agencies to improve coordination with Sound Transit and show measurable progress as they integrate service with Sound Transit.

Related: Car-tab confusion: The math behind your bill

On Thursday afternoon, the House Transportation Committee held a work session on these bills and other issues related to Sound Transit and the controversy over increased car-tab fees.