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.


Bay Area Regional Collaborative: Coordinates the planning efforts of the Association of Bay Area Governments (ABAG), the Bay Area Air Quality Management District (BAAQMD), the Bay Conservation and Development Commission (BCDC), and the Metropolitan Transportation Commission (MTC).

Bay Area Partnership

Often referred to simply as “The Partnership,” this is a confederation of the top staff of various transportation agencies in the region, including MTC, public transit operators, county congestion management agencies (CMAs), city and county public works departments, ports, Caltrans and the U.S. Department of Transportation (DOT) as well as environmental protection agencies. The Partnership works by consensus to improve the overall efficiency and operation of the Bay Area’s transportation network, including developing strategies for financing transportation improvements.

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 Department of Transportation: The state agency that maintains and operates California’s highway system.

Capital Funds

Moneys to cover one-time costs for construction of new projects — such as roads, bridges, bicycle/pedestrian paths, transit lines and transit facilities — to expand the capacity of the transportation system, or to cover the purchase of buses and rail cars.


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.

Committed Projects

Projects that are currently under construction or design with 100 percent committed revenues, as well as projects that will be funded 100 percent with local sales tax revenues.

Committed Revenues

Funds that are directed to a specific entity or for a specific purpose as mandated by statute or by the administering agency. Committed revenues comprise the vast majority of all funds identified in the long-term regional transportation plan. 


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.

Congestion Pricing

A policy designed to allocate roadway space more efficiently by charging drivers a fee that varies with the level of traffic on a congested roadway. (See also Value Pricing.)


County transportation agencies. (See CMAs).


California Transportation Commission: A state-level commission, consisting of nine members appointed by the governor, which establishes priorities and allocates funds for highway, passenger rail and transit investments throughout California. The CTC adopts the State Transportation Improvement Program, or STIP, and implements state transportation policy.


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.

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.

Regional Equity Working Group

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.)


Federal Highway Administration: U.S. Department of Transportation agency responsible for administering the federal highway aid program to individual states, and helping to plan, develop and coordinate construction of federally funded highway projects. FHWA also governs the safety of hazardous cargo on the nation’s highways.

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.

Flexible Funding

Unlike funding that flows only to highways or only to transit by a rigid formula, this is money that can be invested in a range of transportation projects. Examples of flexible funding categories include the Surface Transportation Program (STP) and the Congestion Mitigation and Air Quality Improvement (CMAQ) program.


Freeway Performance Initiative: MTC’s effort to improve the operations, safety and management of the Bay Area’s freeway network via deploying system management strategies, completing the high-occupancy vehicle (HOV) lane system, addressing regional freight issues and closing key freeway infrastructure gaps.


Federal Transit Administration: U.S. Department of Transportation agency that provides financial and planning assistance to help plan, build and operate rail, bus and paratransit systems. The agency also assists in the development of local and regional traffic reduction programs.

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.

HOV Lane

High-Occupancy Vehicle Lane: The technical term for a carpool lane, commuter lane or diamond lane.

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.

Non-Committed Projects

Projects that seek discretionary funds from Plan Bay Area, as well as projects that have not yet completed an Environmental Impact Report (EIR).


Door-to-door bus, van and taxi services used to transport elderly and disabled riders. Paratransit is sometimes referred to as dial-a-ride service, since trips are made according to demand instead of along a fixed route or according to a fixed schedule.


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.

Performance Measures

Indicators of how well the transportation system or specific transportation projects will improve transportation conditions.

Place Types

A place type groups neighborhoods or centers with similar sustainability characteristics and physical and social qualities, such as the scale of housing buildings, frequency and type of transit, quality of the streets, concentration of jobs, and range of services. For Plan Bay Area, Place Types are a tool of local-regional exchange to identify places and policies for sustainable development. Bay Area jurisdictions can select a place type to indicate their desired level of growth in the Sustainable Communities Strategy.

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)



Particulate Matter: A mixture of tiny solid and liquid particles – such as those from dust, dirt, soot or smoke – that are found in the air. When inhaled, these particles can settle deep in the lungs and cause serious health problems.

Potential New Revenues

Funds that may be available for transportation investment in the future if proposed new revenue sources are approved. These potential revenues are not included in the financially constrained portion of long-term transportation plans and Plan Bay Area.

Preferred Scenario

Consideration of the detailed scenario alternatives led to a preferred scenario. (See also Scenarios)


(1) verb, to assign funds to a project that has been approved by MTC, the state or another agency, and (2) noun, a system of funding for implementing transportation projects or policies.


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.

Resolution No. 3434

MTC adopted Resolution 3434 in December 2001 to establish clear priorities for the investment of transit expansion funds over the next decade. It focused on identifying high-priority rail and express/rapid bus improvements to serve the Bay Area’s most congested corridors.


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 Improvement Program: A listing of highway, local road, transit and bicycle projects that the region hopes to fund; compiled by MTC every two years from priority lists submitted by local jurisdictions. The California Transportation Commission (CTC) must either approve or reject the RTIP in its entirety. Once the CTC approves an RTIP, it is combined with those from other regions to comprise 75 percent of the funds in the State Transportation Improvement Program or STIP. (Also see “STIP.”)


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.

Sales Tax Authority

An agency that administers a voter-approved county transportation sales tax program; in most Bay Area counties, the congestion management agency (CMA) also serves as the sales tax authority.

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.

Smart Growth

A set of policies and programs designed to protect, preserve and economically stimulate established communities, while protecting valuable natural and cultural resources and limiting sprawl.


State Transportation Improvement Program: What the California Transportation Commission (CTC) ends up with after combining various RTIPs, as well as a list of specific projects proposed by Caltrans. Covering a five-year span and updated every two years, the STIP determines when and if transportation projects will be funded by the state. Projects included in the STIP must be consistent with the long-range transportation plan.


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 all 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).

Title VI

Refers to Title VI of the Federal Civil Rights Act of 1964, and requires that transportation planning and programming be nondiscriminatory on the basis of race, color and national origin. Integral to Title VI is the concept of environmental justice.


Transit-Oriented Development: A type of development that links land use and transit facilities to support the transit system and help reduce sprawl, traffic congestion and air pollution. It includes housing, along with complementary public uses (jobs, retail and services), located at a strategic point along a regional transit system, such as a rail hub.

TOD Policy

To promote cost-effective transit, ease regional housing shortages, create vibrant communities and preserve open space, MTC adopted a Transit-Oriented Development (TOD) Policy in 2005 that applies to transit extension projects in the Bay Area. Research shows that residents living within half a mile of transit are much more likely to use it, and that large job centers within a quarter mile of transit draw more workers on transit.

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.

Value Pricing

The concept of assessing higher prices for using certain transportation facilities during the most congested times of the day, in the same way that airlines offer off-peak discounts and hotel rooms cost more during prime tourist seasons. Also known as congestion pricing and peak-period pricing, examples of this concept include higher bridge tolls during peak periods or charging single-occupant vehicles that want to use carpool lanes. (See also Congestion Pricing.)


One vehicle (whether a car carrying one passenger or a bus carrying 30 people) traveling one mile constitutes a vehicle mile. VMT is one measure of the use of Bay Area freeways and roads.