Highway Safety Bill Mandates 4:1 Growth Ratio for Funding, Shifting Money Starting 2026

The “Safety Funding Parity Adjustment Act of 2025” is a piece of legislation that dives deep into the weeds of federal highway safety funding, specifically targeting how the Department of Transportation (DOT) distributes money from two major pots: Section 402 funding (general highway safety programs) and Section 405 funding (specific safety programs). Starting October 1, 2026, the Secretary of Transportation must run a complex calculation every year before distributing these funds. The main goal? To ensure that the growth rate of Section 402 funding is exactly four times the growth rate of Section 405 funding when both funds increase.

The Bureaucratic Balancing Act

Think of this bill as installing a mandatory, complex gear system between two funding streams. If both Section 402 and Section 405 funding increase from the previous year, the Secretary has to step in and adjust them. Unless the 402 increase is already four times greater than the 405 increase, the Secretary must proportionally reduce the 405 money and transfer that amount over to 402, making the final growth ratio precisely 4:1. This means that even if Congress allocates more money to specific safety initiatives under Section 405, a chunk of that increase could be immediately siphoned off to boost the general safety programs under Section 402, purely to satisfy this ratio requirement.

What Happens When One Fund Shrinks?

The bill gets even more complicated if Section 405 increases while Section 402 funding actually decreases. In this scenario, the Secretary must use the increase from Section 405 to try and bring Section 402 back up to its previous year’s level. If the 405 increase is substantial, the bill still mandates an adjustment to ensure the 4:1 growth parity is met. This means that Section 405 programs—which might fund critical, targeted efforts like impaired driving campaigns or motorcycle safety—are essentially being used as a mandatory backup fund to prop up the general Section 402 programs whenever 402 funding lags.

The Real-World Impact on Safety Programs

For state and local transportation safety agencies, this bill introduces a new layer of budget uncertainty. Imagine a state agency relying on a planned increase in targeted Section 405 money to launch a new pedestrian safety initiative. Because of this mandated adjustment formula, that anticipated increase could be significantly reduced or entirely transferred to the general 402 fund before it even reaches the state. This makes it harder for local agencies to plan specific, multi-year projects that rely on the targeted funding stream, as the money is now subject to being shifted around based on a federal ratio that doesn’t necessarily reflect local needs or the success of the 405 programs themselves. While the bill aims for funding parity, it achieves it by making the growth of Section 405 perpetually subservient to the growth of Section 402, potentially limiting resources for targeted safety efforts.