Connect SoCal FAQs


Local Data Exchange (LDX) Frequently Asked Questions

1. What is the Local Data Exchange (LDX) process?

The Local Data Exchange is the main opportunity for cities and counties to provide input into Connect SoCal 2024, Southern California’s next Regional Transportation Plan/Sustainable Communities Strategy.

2. Why did SCAG initiate the LDX process?

The input received through the LDX process will help SCAG generate a Forecasted Regional Development Pattern for Connect SoCal 2024 that identifies how and where the region will accommodate anticipated growth. SCAG is mandated by statute to generate a Forecasted Regional Development Pattern to help meet required greenhouse gas emissions and Clean Air Act targets and ensure the region can thrive in the coming decades.

3. What type of information and data did SCAG use in the preliminary growth projections?

SCAG staff, in consultation with an expert panel, the Population Reference Bureau, and the Center for Continuing Study of the California Economy jointly developed a projection of population, households, and employment for the SCAG region and its six counties based on demographic and economic data and expert insights (details can be found here).

The preliminary projection for households at the jurisdiction and Transportation Analysis Zone (TAZ) levels is based on data from general plan capacity retrieved from and updated by local jurisdictions. The preliminary household growth projection also uses draft 6th cycle housing element updates to refine its estimates. In order to help the plan reach statutory targets, the preliminary household growth projection also prioritizes growth in four types of Priority Development Areas (though, not exclusively) and minimizes (but does not preclude) growth in ten types of Green Region Resource Areas. More information about these areas can be found in any jurisdiction’s Data/Map Book starting on page 13.

The preliminary growth projections are intended to set Connect SoCal 2024 on a path toward hitting the statutory greenhouse gas and air quality goals of the Forecasted Regional Development Pattern.

4. Does the preliminary household growth forecast include a local jurisdiction’s Regional Housing Needs Assessment (RHNA) allocation?

The preliminary household growth forecast does include housing element data with the understanding that updates are ongoing and additional local review is a necessary step.

Connect SoCal 2024 will consider the potential for increased household growth resulting from the 6th cycle RHNA, housing element updates and funding programs designed to support their implementation. The plan will also consider that increased household growth may or may not be impacted by the ability and resources to increase development.

5. Who will participate in the LDX process?

The LDX process is a data exchange between SCAG and the 197 local jurisdictions that are the local land-use authorities in the region. SCAG relies upon data and information provided directly by local jurisdictions such as land use and entitlements which drive growth projections . Since Connect SoCal 2024’s projections are not a build-out scenario and entitled projects are often phased over time, SCAG relies on local jurisdictions to assess the development likelihood and timing of key entitlement projects as they review growth projections.

Input is considered complete if approved by a planning director or city manager-level staff using SCAG’s Data Review and Verification Form. In addition, SCAG collaborates directly with the subregional councils of government in Orange, Riverside and San Bernardino counties for outreach and data assistance.

While the LDX process is designed for exchanging certain datasets between local jurisdictions and SCAG, the public is able to view LDX’s draft Data/Map Books online at Connect SoCal 2024’s comprehensive public participation process is set to begin later in 2022.

6. How do local jurisdictions participate in LDX?

SCAG is asking cities and counties to review data layers relating to:

a. Land Use
b. Priority Development
c. Transportation
d. Resource Areas
e. Geographic Boundaries
f. SCAG’s Preliminary Growth Projections

There are several ways to review this data and provide input:

g. Request an LDX account
h. Review the Data/Map Books
i. Complete the planning survey
j. Schedule a one-on-one LDX meeting
k. Complete the Data Review and Verification Form

7. How can local jurisdictions view the data layers?

The draft Data/Map Books and their dynamic online equivalent on the LDX portal both include the data layers that are the main local ingredients to Connect SoCal 2024. This consists of several layers on which SCAG is seeking updates and corrections, other layers on which local updates and corrections are optional, and additional third-party data that relate to regional objectives and are included for reference.

View Only: The draft Data/Map Books are publicly available PDF versions of the data specific to each local jurisdiction and are designed to help local planners better understand the sources, methodologies and contexts of datasets that will be integrated into SCAG’s regional plans.

Review/Update: The LDX online portal contains digital maps of each data layer that local planners can view, edit, and leave comments and feedback on. Using the portal requires no GIS knowledge or software installation. It also allows cities that maintain GIS or data files to securely upload GIS data layers or ArcGIS Urban completed plans.

Unique jurisdictional login information is provided by requesting access here. The SCAG LIST team is available for one-on-one meetings and assistance in using the LDX portal by scheduling a meeting here or emailing SCAG will also accept data or feedback via email in any format.

8. What if a local jurisdiction has corrections or updates or notices errors?

SCAG welcomes input on and changes to the data due to updates in local policies, including entitlements and development agreements. We anticipate that these datasets will require updates in order to accurately reflect local jurisdictions’ assessments.

The Data/Map Books and preliminary growth forecast are still in the draft phase and non-binding at all stages. Local jurisdiction input is critical in making sure we have the most accurate data available. Corrections or updates can be submitted through any of the several ways to provide input outlined in Questions 6 and 7 above.

9. How long will the process take?

On Feb. 23, 2022, SCAG soft-launched the LDX, including the majority of data elements, along with the Regional Data Platform. The LDX complete launch took place on May 23, 2022, and included the planning survey and preliminary growth forecast, also known as Socioeconomic Data. Input and edits are due by Dec. 2, 2022, in order to be included in Connect SoCal 2024.

10. Where can I get help with the LDX process?

Email us at for assistance. In addition to providing a more direct, efficient, and modern link between data, local plans, and SCAG’s regional plan goals, the Regional Data Platform also provides a wide range of planning tools and data as well as custom and off-the-shelf software for local jurisdictions.


Frequently Asked Questions

Connect SoCal Plan (2024 RTP/SCS)

What is SCAG?

Founded in 1965, the Southern California Association of Governments (SCAG) is an association of local governments and agencies that voluntarily convene as a forum to address regional issues. Under federal law, SCAG is designated as a metropolitan planning organization (MPO) and under state law as a regional transportation planning agency and a council of governments.

The SCAG region encompasses six counties (Imperial, Los Angeles, Orange, Riverside, San Bernardino and Ventura) and 191 cities in an area covering more than 38,000 square miles.

The agency develops long-range regional transportation plans that include sustainable communities strategies and growth forecasts, regional transportation improvement programs, regional housing needs allocations, and a portion of the South Coast Air Quality management plans.

What is Connect SoCal 2024?

Connect SoCal 2024 (also known as the 2024 Regional Transportation Plan/Sustainable Communities Strategy or RTP/SCS) represents the vision for Southern California’s future, including policies, strategies, and projects for advancing the region’s mobility, economy, and sustainability through 2050. The plan details how the region will address its transportation and land use challenges and opportunities in order to achieve its regional emissions standards and greenhouse gas (GHG) reduction targets. Connect SoCal 2024 will build from the policy direction established in Connect SoCal 2020 as well as more recent policy direction from SCAG’s Regional Council to reflect emerging issues such as equity, resilience, and the economy.

The components of Connect SoCal 2024 are required by federal and state legislation and is an important planning document for the region, allowing project sponsors to qualify for federal funding. SCAG is required to update this long-range planning document every four years.

What is included in Connect SoCal 2024?

Connect SoCal 2024 contains the following core components:

  • Vision, policies, and performance measures: Contains an overarching vision, policies, a list of regional transportation goals, and measures for evaluating our performance in achieving those goals.
  • Forecasts: Future distribution of population, households, employment, land use, and housing needs.
  • Financial plan: Identifies reasonable expected revenues over the 25-year plan horizon.
  • List of projects: Includes projects that are anticipated to be initiated and/or completed by 2050.
  • Analysis of the following focus areas: active transportation, aviation, environmental justice, goods movement, highways and arterials, land use, open space farm and natural lands conservation, passenger rail and transit, public health, transportation demand management, and transportation safety and security.

How are projects selected for inclusion in Connect SoCal 2024?

Early in the planning process, SCAG asks that each of the six county transportation commissions (CTCs) submit updated project lists for inclusion. The CTCs are responsible for adding, removing, or updating projects from the 2020 RTP/SCS based on jurisdictional needs. These projects are then considered for inclusion in Connect SoCal 2024.

What is SCAG’s role in developing Connect SoCal 2024?

SCAG is the lead agency in facilitating the development of the region’s long-range transportation planning. SCAG understands the importance of input and consensus, and utilizes a collaborative process over several years to create Connect SoCal 2024. This includes working with local jurisdictions through a process known as the Local Data Exchange (LDX) as well as working directly with county transportation commissions (CTCs). Throughout the development of Connect SoCal, SCAG staff are guided by its Policy Committees, CTCs, subregions, local governments, several state and federal agencies (including Caltrans), environmental and business communities, tribal governments, non-profit groups, as well the general public. The end result of this collaborative process is a collaborative and comprehensive document that reflects public consideration and addresses the region’s needs.

To learn more about the Local Data Exchange, visit the LDX webpage.

How does the Connect SoCal 2024 affect me?

Given the geographic diversity and size of the SCAG region, a coordinated transportation system that is well integrated with land uses and operates efficiently is imperative to the mobility and quality of life of Southern California residents. By employing a regional focus to transportation and land use planning, SCAG seeks to improve the region’s mobility, economy, and sustainability.

And although it doesn’t commit funds to specific projects, Connect SoCal 2024 does set the framework for how transportation tax dollars will be spent in the SCAG region over the coming years and decades. The future of the SCAG region will be shaped by the goals and policies set forth in Connect SoCal 2024.

Why do we need Connect SoCal?

Our region is expected to add nearly 1.7 million people in the next 25 years. Connect SoCal 2024 lays out a vision for accommodating that growth, while at the same time maintaining our quality of life and protecting our environment.

Who will approve Connect SoCal?

Various elements of Connect SoCal will be brought before SCAG’s Policy Committees for review, and then before SCAG’s 86-member Regional Council for approval. The Regional Council is made up of elected representatives from the region’s cities and counties as well as one representative of the Southern California Native American Tribal Governments.

How is the public involved?

As the plan is being developed, SCAG will host a number of interactive community workshops, elected official briefings, and public hearings. Feedback shared will help shape the final plan. Nearing the end of the plan’s development, SCAG will release a draft of Connect SoCal 2024 for a public review and comment period. SCAG is required to respond to or address all comments and responses received during the public review and comment period. The final plan will include a Public Participation & Consultation Technical Report to catalogue and archive comments received.