While we strive to use plain language, acronyms and jargon invariably will creep into many discussions about regional planning issues. For this we apologize and offer a glossary of selected acronyms and terms.

AB 32

Assembly Bill 32: The California Global Warming Solutions Act of 2006; state legislation requiring a statewide reduction in greenhouse gas emissions to 1990 levels or lower by the year 2020.


The Association of Bay Area Governments (ABAG) is the official Council of Governments and regional land use planning agency representing the San Francisco Bay Area's nine counties and 101 cities and towns. Formed in 1961, ABAG provides research and analysis, financial services, and other cost-effective local government service programs; and builds partnerships to address regional economic, social and environmental challenges. 

ABAG Regional Planning Committee

This committee studies and submits matters to the ABAG Executive Board regarding Plan Bay Area; environmental management, housing, and infrastructure planning; special plans and reports from planning task forces or other regional agencies; comprehensive planning policies and procedures; and such other matters as may be assigned by the Executive Board. Members include a minimum of 18 elected officials, including at least one supervisor from each member county and a city representative from each county, as well as not less than 10 citizens representing business, minority, economic development, recreation/open space, environment, public interest, housing, special districts and labor interests.

Call for Projects

Regional agencies use this procedure to solicit competing bids from counties, cities, transit agencies, community-based organizations and other stakeholders for projects to be funded as part of long-range plans.


California Environmental Quality Act: This statute requires state and local agencies to identify the significant environmental impacts of their actions and to avoid or mitigate those impacts, if feasible.

Climate Change

Climate change refers to changes in the Earth’s weather patterns, including the rise in the Earth’s average temperature due to an increase in heat-trapping or “greenhouse gases” (GHGs) in the atmosphere. Climate scientists agree that climate change is a man-made problem caused by the burning of fossil fuels like petroleum and coal. Transportation accounts for about 40 percent of the Bay Area’s GHG emissions. Climate change is expected to significantly affect the Bay Area’s public health, air quality and transportation infrastructure through sea level rise and extreme weather.


Congestion Management Agencies: Countywide agencies responsible for preparing and implementing a county’s Congestion Management Program. CMAs came into existence as a result of state legislation and voter approval of Proposition 111 in 1990. Subsequent legislation made them optional. Most Bay Area counties still have them. Many CMAs double as a county’s sales tax authority. Also known as county transportation agencies (CTAs).


Carbon dioxide: A gas that is emitted naturally through the carbon cycle or through human activities. The largest source of CO2 globally is the combustion of fossil fuels (such as coal, oil and gas) in power plants, automobiles, industrial facilities and other sources. In the Bay Area, the single largest source of CO2 emissions, some 41 percent, comes from transportation sources.


A council of government (COG) is a voluntary, regional organization with state and locally-defined boundaries that delivers a variety of federal, state and local programs. COGs function as a planning organization, technical assistance provider and "visionary" to its member local governments. As such, they are accountable to local units of government and effective partners for state and federal governments. ABAG is the COG for the nine-county San Francisco Bay Area.


A process in which transportation plans and spending programs are reviewed to ensure they are consistent with federal clean air requirements; transportation projects collectively must not worsen air quality.


County transportation agencies. See CMAs.


Environmental Impact Report: State law requires that an EIR be prepared if there is substantial evidence that a project may have a significant effect on the environment. A draft EIR shall be included as part of the review and approval process whenever a public hearing is held on the project. Following adoption of a final EIR, the lead agency makes a decision whether to proceed with the project.

Environmental Justice

This term stems from a Presidential Executive Order to promote equity for disadvantaged communities and promote the inclusion of racial and ethnic populations and low-income communities in decision-making. Local and regional transportation agencies must ensure that services and benefits, as well as burdens, are fairly distributed to avoid discrimination.


At MTC and ABAG, equity means just inclusion into a Bay Area where everyone can participate, prosper and reach their full potential. The racial justice focus is acted upon by investing resources for historically underserved, systemically marginalized groups (including low-income and communities of color) at a scale to meaningfully reverse the disparities in access that diminish the nine-county Bay Area.

Equity Analysis

Consistent with federal requirements for environmental justice, MTC and ABAG will conduct an equity analysis covering Plan Bay Area to determine how the benefits and burdens of the plan’s investment strategy affect minority and low-income communities.

Financial Constraint

A federal requirement that long-range transportation plans include only projects that have a reasonable expectation of being funded, based upon anticipated revenues. In other words, long-range transportation plans cannot be pie-in-the-sky wish lists of projects. They must reflect realistic assumptions about revenues that will likely be available looking forward at least 20 years.

Futures Planning

A new way of looking at long-range planning, focused on exploring divergent what if scenarios to identify strategies that are effective in a wide variety of circumstances. It replaces traditional scenario planning where funding and growth are distributed based on fixed assumptions; instead, the Futures process outlines a variety of potential political, technological, economic and environmental challenges that would impact the lives of Bay Area residents.

Global Warming

See Climate Change.

Greenhouse Gases

Any of the gases — including carbon dioxide, methane and ozone — whose absorption of solar radiation is responsible for the greenhouse effect, in which the atmosphere allows incoming sunlight to pass through but absorbs heat radiated back from the earth’s surface. Greenhouse gases act like a heat-trapping blanket in the atmosphere, causing climate change.

Land Use Model

Used by researchers and planners to identify expected population, jobs and housing growth, and to understand the interactions between land use, transportation, and the economy. Models help planners analyze and test various spatial distributions of jobs, population and land uses and describe to policy-makers and the public about the relationship between land use and transportation.


Metropolitan Planning Organization: A federally required planning body responsible for the transportation planning and project selection in its region; the governor designates an MPO in every urbanized area with a population of over 50,000. MTC is the MPO for the nine-county San Francisco Bay Area.


Metropolitan Transportation Commission: The transportation planning, financing and coordinating agency for the nine counties of the San Francisco Bay Area. Created by the state Legislature in 1970, MTC regularly updates the regional transportation plan, a comprehensive blueprint for the development of transportation facilities in the region; MTC also manages a variety of operational programs such as FasTrak, Clipper and the 511 Traveler Information System.


Priority Conservation Area: Regionally significant open spaces for which there exists a broad consensus for long-term protection and for which public funds may be invested to promote their protection.


Priority Development Area: Locally and voluntarily identified locations within existing communities that present infill development opportunities, and are easily accessible to transit, jobs, shopping and services.


Priority Production Areas: Areas nominated by local governments that are zoned for industrial use or have a high concentration of Production, Distribution and Repair (PDR) activities. These activities are considered for zoning purposes as medium-density commercial and use some heavy machinery under controls that minimize any adverse impacts. The nominating local government is required to have a certified Housing Element.

Plan Bay Area (2013)

Adopted in 2013, Plan Bay Area was the Bay Area’s first regional transportation plan to incorporate a state-mandated Sustainable Communities Strategy. It was a joint effort, led by MTC and ABAG.

Plan Bay Area 2040 (2017)

Plan Bay Area 2040 is the strategic update to Plan Bay Area (2013), and it builds on earlier work to develop an efficient transportation network, provide more housing choices, and grow in a financially and environmentally responsible way. Plan Bay Area 2040 was adopted in 2017.

Plan Bay Area 2050 (2021)

Plan Bay Area 2050 is a long-range plan charting the course for the future of the nine-county San Francisco Bay Area. Plan Bay Area 2050 focuses on four key issues—the economy, the environment, housing and transportation—and identifies a path to make the Bay Area more equitable for all residents and more resilient in the face of unexpected challenges. The Metropolitan Transportation Commission and the Association of Bay Area Governments are expected to adopt Plan Bay Area 2050 in summer 2021.


Regional Advisory Working Group: An advisory group originally set up to advise staff on development of Plan Bay Area. Its membership includes staff representatives of local jurisdictions (CMAs, planning directors, transit operators, public works agencies) as well as representatives from the business, housing, environmental and social-justice communities.


The Regional Equity Working Group was set up to advise MTC and ABAG staff in developing of an equity analysis related to low-income and minority communities of concern for Plan Bay Area. It consists of representatives from MTC’s Policy Advisory Council and the Regional Advisory Working Group (RAWG). (See also Equity Analysis.)


Regional Housing Needs Allocation: The Regional Housing Needs Allocation process is a state mandate regarding planning for housing in California. ABAG is responsible for allocating this state-determined regional housing need among all of the Bay Area’s nine counties and 101 cities. Factors used by ABAG in its allocation process include projected household growth, existing employment and projected employment growth, and projected household and employment growth near transit.


Regional Transportation Plan: A master plan to guide the region’s transportation investments for a 25-year period. Updated every four years, it is based on projections of growth in population and jobs and the ensuing travel demand. Required by state and federal law, it includes programs to better maintain, operate and expand transportation. The Bay Area’s most recent update of its long-range transportation plan is known as Plan Bay Area 2040. The next RTP will be included as a part of Plan Bay Area 2050.

SB 375

Senate Bill 375 (Steinberg): SB 375 became law in 2008. It includes two main statutory requirements and a host of voluntary measures. It is designed to complement AB 32, which requires the state to reduce its GHG emissions to 1990 levels by 2020. The first requirement is to reduce per-capita carbon dioxide (CO2) emissions from cars and light-duty trucks, primarily by building more compact communities with better access to mass transit and other amenities, so people have more transportation choices and do not have to drive as much. The second requirement is to house 100 percent of the region’s projected 25-year population growth, regardless of income level.


Scenarios represent alternative futures based on distinct land use and development patterns and transportation investment strategies.


Sustainability means doing things and using resources in ways that protect them so they will be available for current and future generations. The “Three E” goals of sustainability are Economy, Environment and Equity. Sustainability is about helping support a prosperous and globally competitive economy, providing for a healthy and safe environment, and producing equitable opportunities for all Bay Area residents.

Sustainable Communities Strategy

The Sustainable Communities Strategy (SCS) is an integrated land use and transportation plan that all metropolitan regions in California must complete under Senate Bill 375. In the San Francisco Bay Area, this integration includes ABAG’s Projections and Regional Housing Needs Allocation (RHNA) and MTC’s Regional Transportation Plan (RTP).

Travel Model

Used by researchers and planners for simulating current travel conditions and for forecasting future travel patterns and conditions. Models help planners and policy-makers analyze the effectiveness and efficiency of alternative transportation investments in terms of performance, such as mobility, accessibility, environmental and equity impacts.