ITIF-征收卡车行驶里程税以提高美国道路的可持续性（英）-2025.7_15页_417kb

Summary of "A Truck Mileage Traveled Tax to Enhance US Roadway Sustainability"

Core Content

This document explores the inadequacy of the current U.S. Highway Trust Fund (HTF) funding model, which relies primarily on a flat-rate fuel tax that has not been adjusted for inflation. It argues that this outdated system leads to underfunding of the Interstate Highway System and encourages inefficient and harmful trucking behaviors. The proposed solution is an axle-adjusted vehicle mileage traveled tax (VMTT), which would better reflect the damage caused by trucks and provide a more equitable and sustainable funding mechanism.

Main Points

1. Current Funding Structure is Inefficient

• The HTF is funded mainly through fuel taxes, which have not kept pace with inflation since 1993.
• Fuel taxes are regressive and fail to account for the actual damage caused by trucks, which are responsible for a disproportionate share of road deterioration.
• The HTF is projected to be short by $188 billion by 2030 due to the inadequacy of the fuel tax model.

2. Trucking Industry's Impact on Road Infrastructure

• Freight trucks, though a small portion of total vehicle miles, cause significant damage to the road network.
• The fourth power rule demonstrates that road damage increases exponentially with truck weight.
• Trucks contribute to 40% of federal highway costs but generate only ~13% of HTF revenues, highlighting the misalignment between cost and payment.

3. Need for an Alternative Tax Structure

• The VMTT is proposed as a more accurate and equitable method of funding road infrastructure.
• Unlike fuel taxes, VMTT can be adjusted for both distance and weight, and even axles, to better capture the actual damage trucks cause.
• A VMTT on trucks could reduce road damage, improve safety, and promote environmental sustainability.

4. Implementation Experience in the U.S. and Abroad

• Four U.S. states (Kentucky, New York, New Mexico, Oregon) have implemented VMTT or similar systems.
• These programs have shown that VMTT can be effective in reducing truck usage and aligning costs with usage.
• In Switzerland, a VMTT reduced truck numbers by 4.7% to 5.1%.

5. Proposed Efficient VMTT Structure

• The tax should be based on ton-mile and axle load to reflect the damage caused.
• A weight-distance tax is recommended, with axle-adjusted rates to ensure fairness and efficiency.
• The document suggests a range of 1 to 13 cents per mile for single-unit trucks and 1 to 19 cents per mile for combination trucks.
• The average VMTT for all trucks is estimated at 4.6 cents per mile.

Key Information

6. Tax Calculation and Data Assumptions

• The tax calculation is based on 2023 HTF outlays and 2022 truck miles.
• The HTF deficit due to trucks is estimated at $8.3 billion for combination trucks and $2.3 billion for single-unit trucks.
• The VMTT rate per mile is calculated as the deficit divided by total miles, resulting in 5.3 cents per mile for combination trucks and 3.2 cents per mile for single-unit trucks.
• The blended VMTT for all truck types is 4.6 cents per mile.

7. Impact of Weight and Axles on Damage

• Road damage is a function of truck weight, number of axles, and distance traveled.
• The fourth power law is used to adjust the VMTT for weight, ensuring that heavier trucks pay more.
• Axle adjustments help reduce the per-axle weight, thereby mitigating damage.
• The VMTT per axle ton mile is calculated by applying the fourth power rule and adjusting for axle load.

8. Environmental and Safety Considerations

• The VMTT should also account for greenhouse gas emissions, air pollution, noise, and accident costs.
• The tax should be adjusted for location and congestion, though these are left to local authorities.
• The HTF is primarily used to fund interstate highways, so the focus of the tax is on interstate and rural road usage.

9. Policy Recommendations

• The VMTT should be implemented alongside existing fuel taxes.
• It should be axle-adjusted to reflect the weight distribution and damage per axle.
• The tax should be progressive, with heavier trucks paying more.
• The optimal VMTT for single-unit trucks is 0.1 to 18 cents per mile, and for combination trucks is 1.4 to 20 cents per mile.

Conclusion

The axle-adjusted VMTT is a more efficient and equitable method of funding the U.S. Interstate Highway System. It addresses the inequity of the current fuel tax system and aligns costs with usage, thereby reducing road damage, improving safety, and supporting long-term sustainability. The document proposes a specific range of VMTT rates for different truck types and emphasizes the importance of axle adjustment to ensure fairness and efficiency. This tax model is seen as a practical first step toward a broader VMTT system for all vehicles.