The Highway Safety Improvement Program is the federal government’s main funding source for reducing traffic deaths and serious injuries on public roads in the United States. It sends money to every state by formula, but the money comes with strings: states must have an approved safety plan, pick projects through data-driven analysis, and report annually on results. For fiscal year 2026, Congress authorized $3.246 billion in contract authority for the program.
How the Money Gets to States
HSIP funds reach states through apportionment. Each fiscal year, the Secretary of Transportation calculates each state’s share of the national total using a formula tied to factors like road mileage and population. HSIP receives 6.7 percent of a state’s base federal-aid apportionment after certain other programs take their shares first.
The obligation authority for fiscal year 2026 runs from October 1, 2025 through September 30, 2026. Any unobligated limitation expires at the end of that fiscal year, so money a state fails to commit to approved projects can effectively be lost. Before any HSIP apportionment goes out, the Secretary also sets aside at least $245 million nationally for railway-highway crossing improvements, taken off the top of the HSIP pot.
Federal Share and State Match
The default federal share is 80 percent of project costs, with the state covering the remaining 20 percent. That ratio can increase slightly for states with large amounts of nontaxable federal or tribal lands, but it caps at 95 percent.
Many common safety projects qualify for a 100 percent federal share, meaning no state match is required. Fully federally funded improvements include traffic signal installation, pavement markings, roundabouts, shoulder and centerline rumble strips, guardrails, crash attenuators, breakaway utility poles, priority control systems for emergency vehicles at signalized intersections, and rail-highway crossing closures. There’s a limit on the aggregate: no more than 10 percent of all federal-aid highway funds apportioned nationally in a given year can go toward these fully funded projects.
What Projects Qualify
Federal law defines a highway safety improvement project as any strategy, activity, or project on a public road that is consistent with the state’s Strategic Highway Safety Plan and either corrects a hazardous road location or addresses a highway safety problem. The statute lists more than 30 specific eligible project categories. The most commonly funded include:
- Intersection improvements such as signal timing upgrades and roundabouts, including changes that improve safety for pedestrians and cyclists
- Pavement and shoulder widening, including passing lanes that remedy unsafe conditions
- Rumble strips and warning devices, provided the installation doesn’t harm safety or mobility for cyclists, pedestrians, or people with disabilities
- New or upgraded signs and pavement markings, including projects maintaining minimum retroreflectivity
- Guardrails and barriers, including barriers between construction work zones and traffic lanes
- Pedestrian and bicycle safety infrastructure, and yellow-green signs and signals at crossings and school zones
- Traffic calming features and road designs that reduce vehicle speeds
- Structures and measures to prevent vehicle-wildlife collisions
- Removing or shielding fixed objects near travel lanes
- Construction and operational upgrades on high-risk rural roads
Eligibility also covers safety data collection and analysis, road safety audits, transportation safety planning, and geometric improvements made specifically for safety purposes.
Non-Infrastructure Projects
HSIP funding isn’t limited to physical infrastructure. Road safety audits, enforcement activities, and safety data improvements can qualify too. Any non-infrastructure project must address a priority in the state’s Strategic Highway Safety Plan, be selected through a data-driven process based on crash experience or risk analysis, target an identified safety problem, and contribute to reducing fatalities and serious injuries. Specific eligibility varies, so agencies considering non-infrastructure spending typically check with their state DOT or the FHWA Division Office.
The Strategic Highway Safety Plan
No state can spend HSIP money without a Strategic Highway Safety Plan, known as the SHSP. Federal law requires every state to develop and regularly update this multi-year blueprint, which coordinates safety efforts across agencies and disciplines. A state without an approved updated SHSP loses eligibility to receive redistributed federal obligation authority after August 1 of each fiscal year until the plan is approved.
The SHSP must account for a range of safety considerations: the locations of fatalities and serious injuries, locations that lack crash history but carry risk factors, rural roads (including all public roads proportionate to their fatality data), pedestrian and bicyclist crashes, cost-effectiveness of proposed improvements, rail-highway grade crossing safety, and safety on non-state-owned public roads and tribal land.
The statute also mandates consultation with at least ten categories of stakeholders, ranging from the Governor’s highway safety representative and state and local traffic enforcement officials to metropolitan planning organizations, county transportation officials, and representatives of nonmotorized road users. That consultation requirement keeps enforcement, behavioral, education, and infrastructure perspectives all in the final product.
Vulnerable Road User Requirements
The Infrastructure Investment and Jobs Act added protections for vulnerable road users, defined in the statute as nonmotorists, people with disabilities, people on bicycles (including electric bicycles and electric scooters), and motorcyclists. The requirements have two parts.
The Safety Assessment
Every state must complete a vulnerable road user safety assessment that includes a quantitative analysis of fatalities and serious injuries involving these users. The analysis must incorporate location data, roadway functional classification, design speed, speed limits, and time of day. The law also requires states to consider the demographics of crash locations, including race, ethnicity, income, and age. Based on that data, states identify high-risk areas and develop a program of projects or strategies to reduce those risks. The assessment must use at least five years of the most recent available data, take a safe system approach, and involve consultation with local governments and planning organizations representing high-risk areas. The projects that come out of it cannot degrade transportation system access for the people they’re meant to protect.
The 15 Percent Spending Rule
If vulnerable road user fatalities account for 15 percent or more of a state’s total annual crash fatalities, the state must obligate at least 15 percent of its HSIP apportionment the following fiscal year specifically for projects addressing vulnerable road user safety.
Railway-Highway Crossings
A dedicated slice of HSIP funding goes to the Railway-Highway Crossings Program. The Secretary sets aside at least $245 million per year from the HSIP pot for fiscal years 2022 through 2026 to address hazards where trains and motor vehicles intersect. The money funds protective devices like flashing lights and automatic gates, replacement of outdated warning systems, and grade separation projects that eliminate the conflict point by building a bridge or underpass.
Every state must conduct and maintain an ongoing survey of all highways to identify crossings that may need separation, relocation, or protective devices, and then implement a prioritized schedule of improvements. At a minimum, the schedule must provide signs for every railway-highway crossing in the state.
The Safe System Approach
HSIP project selection has been moving away from the traditional “hot spot” method, which waits for crashes to accumulate at a location before fixing it, toward the Safe System Approach. Rather than only targeting intersections where crashes have already piled up, safety engineers analyze roadway characteristics across entire networks to find locations with elevated crash potential, even if no serious crash has occurred there yet. Tools like Safety Performance Functions and the Empirical Bayes method help states rank locations by potential for safety improvement rather than by historical crash count. State DOTs using this approach have found that it broadens investment beyond dense urban corridors and channels more funding toward low-cost systemic improvements, such as installing rumble strips during routine resurfacing.
Reporting and Performance Targets
Every state must submit an annual report to the Secretary of Transportation describing its progress implementing HSIP projects and assessing their effectiveness. The report breaks down reductions in fatalities and serious injuries on all public roads by functional classification and ownership, to the extent practicable, and specifically addresses fatalities and serious injuries at railway-highway crossings.
States also set annual safety performance targets across five measures:
- Total number of fatalities
- Fatality rate per 100 million vehicle miles traveled
- Total number of serious injuries
- Serious injury rate per 100 million vehicle miles traveled
- Number of nonmotorized fatalities and serious injuries
Federal law also protects the underlying data. The reports, surveys, schedules, and data compiled for HSIP purposes cannot be used as evidence in any federal or state court proceeding or considered in damage lawsuits arising from crashes at locations identified in the data.
What Happens When States Miss Their Targets
If the Secretary determines a state has not met or made significant progress toward its safety performance targets, the consequences are concrete. The state must dedicate its entire HSIP obligation authority, equal to the prior year’s apportionment, exclusively to highway safety improvement projects until the Secretary is satisfied with the state’s progress. There is no flexibility to shift those funds elsewhere. The state must also submit an annual implementation plan that identifies hazardous roadway features, lists projects selected through data-driven analysis, describes how HSIP funds will be allocated, explains how proposed projects will advance the state’s safety targets, and details specific actions the state will take to get back on track. The restriction and the planning requirement continue every year until the state demonstrates adequate progress.