Measure M Los Angeles: Transportation Sales Tax and Projects

Measure M is a half-cent sales tax approved by Los Angeles County voters in November 2016 to fund an expansive, multi-decade transportation program administered by the Los Angeles County Metropolitan Transportation Authority. The measure generates billions of dollars annually for rail, bus rapid transit, highway improvements, and active transportation projects across the county. Understanding its structure, funding allocations, and project timelines is essential for residents, policymakers, and local governments navigating how regional mobility investments are planned and delivered.

Definition and scope

Measure M — formally known as the Los Angeles County Traffic Improvement Plan — was placed on the November 2016 ballot by the Los Angeles Metro Board of Directors and approved by 71.15% of Los Angeles County voters, surpassing the two-thirds supermajority threshold required under California's Proposition 218 for special taxes. The measure imposes a permanent half-cent (0.5%) transactions and use tax on retail sales within Los Angeles County.

Measure M does not have a sunset date. Unlike its predecessor, Measure R — a separate half-cent sales tax approved in 2008 with a 30-year term — Measure M runs indefinitely, producing a stable, long-term funding stream. Combined, Measures R and M together impose a full cent (1.0%) of sales tax dedicated to transportation within the county.

The tax applies to taxable retail transactions occurring within Los Angeles County's geographic boundaries. Exemptions follow the standard California sales and use tax framework administered by the California Department of Tax and Fee Administration (CDTFA): groceries, prescription medications, and certain agricultural inputs are excluded from the base.

Scope, coverage, and limitations: Measure M revenue is restricted to Los Angeles County. It does not fund transportation projects in Orange County, San Bernardino County, Ventura County, or Riverside County, even where those jurisdictions connect to Metro-operated corridors. Projects in the Southern California Regional Rail Authority service area — including Metrolink commuter rail — may receive Measure M contributions only through specific programmatic allocations. Cities outside Los Angeles County, such as Pasadena, Long Beach, or Santa Monica, benefit from Measure M only to the extent that funded projects serve their jurisdictions as part of the countywide network. The measure does not govern operations at Los Angeles World Airports or the Port of Los Angeles, which maintain separate capital funding mechanisms.

How it works

Measure M revenue flows through a structured allocation formula set by the ballot ordinance. The Los Angeles Metro funding and budget framework integrates Measure M alongside federal formula grants, state transportation funds, and Measure R proceeds.

The allocation breaks down as follows:

1. 40% — Transit Capital and Operations: Funds construction and operating costs for new and existing rail and bus rapid transit lines, including the Purple Line Extension, the East San Fernando Valley Transit Corridor, and the West Santa Ana Branch.
2. 17% — Highway Capital Improvements: Directed to freeway and arterial improvements, including high-occupancy vehicle (HOV) lane additions and interchange upgrades.
3. 3% — Active Transportation: Supports bicycle lanes, pedestrian infrastructure, and first/last-mile connectivity.
4. 2% — Local Return — Cities and County: A direct pass-through to Los Angeles County's 88 municipalities and unincorporated county areas, distributed on a per-capita basis for locally controlled transportation spending.
5. 35% — Remaining Transit Programs and Debt Service: Covers Express Lanes, multi-modal programs, and debt service on bonds issued against future revenue.

Metro issues revenue bonds backed by projected Measure M receipts, allowing construction to proceed years ahead of the tax revenue that will ultimately retire the debt. The Metro Board of Directors approves the annual budget and capital program, while an independent taxpayer oversight committee — the Measure M Independent Taxpayers Advisory Committee (ITAC) — reviews expenditures for compliance with the ballot measure's spending plan.

Common scenarios

Scenario: A municipality seeks local return funds. Each of the 88 cities within Los Angeles County receives a proportional share of the 2% local return allocation. A city such as Inglewood or Compton applies those funds toward locally designated transportation improvements — street repaving, traffic signal upgrades, or bicycle infrastructure — subject to Metro's local return guidelines.

Scenario: A major rail project is accelerated. Metro can sell bonds against anticipated Measure M revenue to begin construction before the tax has accumulated sufficient cash. The Purple Line Extension to Westwood, for example, draws on bonded proceeds as well as Federal Transit Administration (FTA) Capital Investment Grants, with Measure M providing the local match required to access federal funding.

Scenario: Measure M vs. Measure R on the same project. Both taxes may fund a single corridor. The Crenshaw/LAX Line, for instance, drew on Measure R for initial phases; Measure M provides ongoing capital and operations funding for extensions. The two measures are legally distinct, tracked separately in Metro's budget, and each governed by its own expenditure plan.

Decision boundaries

Several boundaries determine whether a project or expenditure qualifies under Measure M:

Geographic boundary: Only projects within Los Angeles County qualify. A cross-county extension requires a funding agreement with the adjacent transit agency; Measure M cannot unilaterally fund capital outside county lines.

Expenditure plan conformance: Every project funded by Measure M must appear in — or be consistent with — the approved Expenditure Plan. Amendments to the plan require approval by the Metro Board and, for material changes, may require voter ratification under California law.

Tax base boundary: Measure M applies to taxable retail sales. Business-to-business transactions, internet sales sourced outside California, and sales tax–exempt goods do not generate Measure M revenue regardless of where the buyer is located within the county.

Oversight trigger: Expenditures above defined thresholds require ITAC review before Metro certifies compliance. Projects funded outside the plan's categorical allocations require formal board action and public disclosure under the Brown Act, which governs Los Angeles County Board of Supervisors and Metro Board meetings alike.

For a full map of how Measure M fits within Metro's governance and capital planning structure, the Los Angeles Metro Transit Authority overview provides context on the agency's statutory authority, board composition, and intergovernmental relationships across the region.

References

• Los Angeles County Metropolitan Transportation Authority — Measure M
• Los Angeles Metro Expenditure Plan (Measure M Ordinance 16-01)
• California Department of Tax and Fee Administration — Sales and Use Tax
• California Proposition 218 (Article XIII C & D, California Constitution)
• Federal Transit Administration — Capital Investment Grants Program
• Los Angeles Metro Board of Directors — Board Reports
• Los Angeles County Registrar-Recorder — November 2016 Election Results