Regional Transportation Plan (RTP)

What is MOMENTUM?

MOMENTUM is our regional transportation plan (RTP). It provides a broad vision for the region’s multimodal transportation future and serves as a long-term blueprint for our transportation system. MOMENTUM is performance-based and reflects funding the region has programmatic oversight for, including federal, state, and regional revenues. The RTP invests the dedicated half cent sales tax for transportation, approved through Proposition 479, in necessary, resilient, multimodal transportation infrastructure. This infrastructure connects people with opportunities to prosper and thrive.

What is included in MOMENTUM?

MOMENTUM funds regional multimodal transportation over a 25-year period. The plan includes commitments to large capital projects, such as new freeway and high-capacity transit infrastructure, as well as investments in program areas such as safety, air quality, and nonmotorized infrastructure. This programmatic strategy provides greater flexibility and allows the region to be nimble, responding and adapting to an ever-changing future.

History of the RTP

The MAG region is proud of its unique legacy in investing in our transportation system. We would not have the system we have today without a regional commitment to fund multimodal transportation. The RTP creates a vision, but it is regional funding that brings that vision to life.

In 1985, voters passed Proposition 300, beginning the collection of a 20-year, half-cent sales tax focused on establishing the Valley’s freeway network. In 2004, voters approved Proposition 400, a 20-year extension of the dedicated half-cent sales tax to fund multimodal transportation investments, continuing the needed expansion of the region’s system. Combined, the revenue generated from these propositions delivered Loops 101, 202, and 303, light rail and streetcar, arterial street investments, and contributions to a growing multimodal network — a total investment of over $12 billion.

On November 5, 2024, the voters in Maricopa County passed Proposition 479, which extended the current half-cent sales tax for transportation, Proposition 400, which was set to expire on December 31, 2025.

The passage of Proposition 479 ensures the region can move forward with implementation of the transportation vision outlined in MOMENTUM and invest in projects big and small to reduce congestion, improve quality of life, and meet the region’s expected growth.

MOMENTUM Plan Development

Long-range regional transportation planning is a continual, cooperative, and comprehensive process that requires collaboration among many stakeholders. With the sunset of Proposition 400 collections at the end of 2025, MAG embarked on a multi-year planning effort to develop a new investment plan to serve as the basis for Proposition 479. The MOMENTUM planning process kicked off in 2018 with a values mapping effort aimed at understanding public attitudes and perceptions about regional transportation needs and investment priorities. The final report Transportation Values & Priorities in the Maricopa Region served as the plan’s foundation.

Over the next three years, MAG staff worked closely with elected officials to develop the plan. Throughout the entire process, there was continuous public and stakeholder engagement. The Early Phase Public Input Report, Late Phase Public Input Report, and the Fiscal Year 2022 Public Input Report summarize public input and the outcomes of the MOMENTUM engagement efforts, which were directly reported to decision-makers.

Transportation planning is a continuous process, and our work included a robust stakeholder and public engagement strategy. Review our engagement by-the-numbers in the Public Participation and Stakeholder Engagement Stats 2019-2023.

The MAG Regional Council unanimously approved the MOMENTUM 2050 plan on December 1, 2021. The U.S. Department of Transportation (USDOT) issued a Finding of Conformity for MAG’s air quality conformity analysis of the plan on December 15, 2021.

On December 3, 2025, the Regional Council unanimously approved the update to the RTP, MOMENTUM 2050. This update incorporates the region’s Regional Strategic Transportation Infrastructure Investment Plan (RSTIIP), Proposition 400 and 479-funded projects, and updated population, employment, traffic, and travel demand data. The USDOT issued a Finding of Conformity for MAG’s air quality conformity analysis of the plan on January 8, 2026.

Regional Strategic Transportation Infrastructure Investment Plan (RSTIIP)

MAG’s Transportation Policy Committee developed the Regional Strategic Transportation Infrastructure Investment Plan (RSTIIP) to serve as the basis for the transportation investments funded through Proposition 479, as well as other revenues available to the region. The investment plan is a companion to the RTP and is based on MOMENTUM’s planning principles, grounded in community-driven values and priorities, and comprised of specific projects and programs.

The RSTIIP was originally approved by MAG Regional Council on June 23, 2021, with project phasing approved July 28, 2021. The RSTIIP was subsequently modified to reflect conforming changes following the passage of Senate Bill 1102, enabling legislation for the extension of Proposition 400.

Plan Amendments

Periodically, MAG amends the RTP to reflect the changing priorities and needs of our region. MAG documents all plan amendments. To review the latest plan amendments, click below.

Transportation Improvement Program (TIP)

The Transportation Improvement Program (TIP) is a companion to the RTP. Where the RTP is a long-range vision for our transportation future, the TIP is a detailed near-term project listing and, by definition, serves as the first four years of the RTP.

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