This bill amends 23 U.S.C. 133(b) to add a new eligible project category for the Surface Transportation Block Grant Program: construction of roundabouts. That change broadens the set of projects that can be funded with STBG dollars, aligning funding eligibility with common safety and operational improvements at intersections.
The act does not create new funding or require additional appropriations; it simply expands what qualified projects may receive STBG support. The bill’s short title is the Traffic Safety Enhancement Act of 2025.
The introduction signals an intent to facilitate roundabout projects through existing federal-aid highway funding channels.
At a Glance
What It Does
The bill adds a new eligible project category to 23 U.S.C. 133(b): (25) Construction of roundabouts. This expands the list of projects that may be funded with Surface Transportation Block Grant Program funds.
Who It Affects
State Departments of Transportation, metropolitan planning organizations (MPOs), and local governments that deliver STBG-funded highway projects; design-build firms and consultants that implement roundabout projects.
Why It Matters
Roundabouts can improve safety and traffic flow. By placing roundabouts alongside other eligible projects, the bill could influence project selection and funding decisions within the STBG framework.
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What This Bill Actually Does
The Traffic Safety Enhancement Act of 2025 makes roundabouts an eligible use of Surface Transportation Block Grant Program funds by amending 23 U.S.C. 133(b) to add a new item, (25) Construction of roundabouts. This is an eligibility expansion rather than a new funding stream.
Jurisdictions that use STBG funds—state DOTs, regional MPOs, and local governments—can consider roundabouts as acceptable purposes for federal highway dollars, subject to existing program rules, environmental reviews, and procurement processes. The act does not prescribe a funding amount or require a specific rollout; it simply broadens what projects can be funded with the block grant.
Compliance considerations will continue to hinge on standard STBG requirements and federal-aid highway guidelines.
The Five Things You Need to Know
The bill adds roundabouts as an eligible STBG project.
Amendment is accomplished by adding a new item (25) to 23 U.S.C. 133(b).
No new funding is created; eligibility is broadened.
Short title designated as the Traffic Safety Enhancement Act of 2025.
Introduced May 15, 2025 in the 119th Congress by Rep. Laura Gillen.
Section-by-Section Breakdown
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Short title
Section 1 designates the act's official name. It may be cited as the Traffic Safety Enhancement Act of 2025, establishing a formal reference for all future legal and administrative use.
Amendment to the Surface Transportation Block Grant Program
Section 133(b) of title 23, United States Code, is amended by adding at the end the following: (25) Construction of roundabouts. This change expands the pool of eligible projects for STBG funds to include roundabout construction and related safety improvements, without creating new funding or altering funding levels. The amendment relies on existing STBG governance and oversight mechanisms.
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Every bill creates winners and losers. Here's who stands to gain and who bears the cost.
Who Benefits
- State Departments of Transportation (DOTs) and metropolitan planning organizations (MPOs) gain additional project options within the STBG program, potentially accelerating safety-focused improvements.
- Municipalities and counties responsible for local road networks can plan and fund roundabout projects under STBG allocations, enabling targeted intersection upgrades.
- Civil engineers, traffic engineers, and design-build firms specializing in roundabout retrofits or new intersections may see increased demand for planning, design, and construction work.
- Planning staff and grant coordinators can align roundabout projects with existing federal-aid requirements, facilitating submission and management within current processes.
Who Bears the Cost
- State DOTs and MPOs may incur administrative costs to adjust project pipelines and reporting for roundabout eligibility.
- Local governments could face design, environmental permitting, and construction costs associated with roundabout projects that are funded with STBG dollars.
- Federal and state agencies may shoulder additional oversight or compliance administration to ensure roundabouts meet standards and continue to align with STBG requirements.
- Construction firms may incur higher design and execution costs for roundabout projects, especially in areas with site-specific constraints.
Key Issues
The Core Tension
Expanding eligibility to roundabouts could improve safety and traffic flow without increasing funding, but it requires careful prioritization and adherence to existing federal-aid processes to prevent misallocation of limited transportation dollars.
The bill opens the door for roundabouts within an existing funding mechanism, which can yield safety and efficiency gains but also raises questions about project prioritization, capacity, and environmental reviews. Because the act does not allocate funds or alter funding levels, the real-world impact depends on how agencies prioritize roundabout projects within their existing STBG envelopes.
Jurisdictions will need to maintain compliance with federal-aid project requirements, including planning, environmental review, and cost-sharing rules, while integrating roundabout design and construction into their procurement pipelines.
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