SC Road Funding

Federal Funding

Federal Funding plays a critical role in funding our transportation program. It accounts for a significant amount of South Carolina's transportation budget. The primary funding source for federal highway investment in the United States is the excise tax on motor fuels.

Federal Gasoline Tax

18.4¢

per gallon

Federal Diesel Tax

24.4¢

per gallon

Fuel taxes are dedicated to the Federal Highway Trust Fund (HTF). Other revenue sources dedicated to the HTF come from taxes on tires and heavy vehicles (trucks). Due to the decreased buying power of fuel tax revenues over the years, the fund has depended on revenue transfers from other sources to remain solvent.

Infrastructure Investment & Jobs Act (IIJA)

In 2021, Congress passed the Infrastructure Investment & Jobs Act (IIJA), which reauthorized surface transportation funds through 2026 and increased federal funding to states. Thanks to the IIJA, South Carolina is receiving approximately $250 million more in federal formula funding (roughly $1 billion, up from $750 million). Revenue sources for the IIJA come from various sources, including general funds.

State Revenue Sources

South Carolina's transportation infrastructure revenue sources come from motor fuel user fees and other vehicle-related fees. State revenue sources are used to match federal fund requirements, and they are critical to funding maintenance and repairs.

Motor Fuel User Fees

The state's predominant source for transportation infrastructure comes from motor fuel. Often referred to as the "gas tax," the state collects a 28.75 cents per gallon user fee on motor fuel (gasoline and diesel) purchased in South Carolina.

Infrastructure Maintenance Fee

This fee is imposed on purchasing or transferring vehicle registration from another state. The fee is 5% for in-state purchases (capped at $500) and $250 for out-of-state transfers.

Biennial Registration Fees

$16 of the biennial registration fee for passenger vehicles.
$120 from the biennial registration fee on electric vehicles
$60 from the biennial registration fee on hybrid vehicles

Road Use Fee on Commercial Vehicles

Fee varies and is based on property tax formulas and captures revenues from interstate trucking operations. Most of these fees go to counties and are treated like property tax revenues; however, the remainder is dedicated to the SCDOT’s Infrastructure Maintenance Trust Fund.

DMV Fines and Fees

Many fines and fees related to licensing and titling requirements are allocated to the SCDOT.

Other Revenues

The SCDOT also receives revenues from various sources, including but not limited to fines, permits, and interest. In addition, the agency receives $120 million in recurring general funds from the state budget annually.

South Carolina uses these recurring revenues to repair, maintain, and improve the state's transportation network. On average, over 82% of SCDOT's yearly expenditures go directly toward maintenance, preservation, and capacity improvements to existing roads and bridges.

Dedicated, recurring revenue sources are the lifeblood of successful transportation programs. They provide stability for planning by the public and private sectors responsible for putting these dollars to work. Most importantly, dedicated revenue sources provide transparency for taxpayers.

Local Funding

A portion of state revenues from gasoline taxes (3.99 cents) goes directly to counties via C-Funds allocated to County Transportation Committees (CTC). CTCs are a partnership between the state and the counties to fund local transportation projects and improvements to state and county roads and city streets. Generally, members of the CTC may be appointed by their respective legislative delegation or governing bodies at the local level. CTCs are separate entities from SCDOT, and members of the CTC are responsible for determining how money is spent across the county.

C-Funds are allocated based on a formula that takes into account land area, population, and rural road mileage. By law, CTCs must spend at least 33 percent of their C-Funds on the state highway system for construction, improvements, and maintenance.

Other local funding sources vary by county and municipality. However, counties in South Carolina may impose a local option sales tax via referendum to fund transportation improvements. Learn more about local option sales taxes here.