Travel Demand Model (TDM)

Trvel Demand Model

The framework of the Travel Demand Model (TDM) updated in 2014 is complete.  The TDM is not a static, unchanging, fixed planning tool. It must be maintained, updated and improved over time to remain useful and relevant. The County completed several projects, including the major 5-Year update of the Capital Improvement Program (CIP), and the Traffic Impact Mitigation (TIM) Fee Program. The TDM may be updated as additional data is received during the course of these projects.

During the TDM update, County staff coordinated with Caltrans and the Sacramento Area Council of Governments (SACOG) since 2012 as part of the process to update the County’s TDM. On February 3, 2014, SACOG provided a letter of concurrence based on ongoing dialog with County staff. County and Caltrans staff have worked to fine-tune the TDM to address any remaining questions. As a result of this close collaboration, the County received a letter from Caltrans on September 22, 2014 stating their concurrence with the TDM and finding that it “conforms to the state-of-practice in travel demand modeling; meets overall traffic assignment validation standards suggested by FHWA and Caltrans; and is an appropriate tool for the County’s long range planning purposes." (See Supporting Documents for Caltrans and SACOG letters.)

​Backgound Information

A Travel Demand Model (sometimes referred to as a Traffic Demand Model) is a tool for analyzing the impacts of development on the transportation system. The County’s previous travel demand model (TDM) was based on a software platform with limited capability that is no longer supported. The new TDM was developed in the CUBE/Voyager platform, using 2010 Census data and updated socioeconomic data from several sources including information from the Sacramento Area Council of Governments (SACOG). The model has a forecast horizon year of 2035.

During the TDM update, County staff coordinated with Caltrans and the Sacramento Area Council of Governments (SACOG) since 2012 as part of the process to update the County’s TDM. On February 3, 2014, SACOG provided a letter of concurrence based on ongoing dialog with County staff. County and Caltrans staff have worked to fine-tune the TDM to address any remaining questions. As a result of this close collaboration, the County received a letter from Caltrans on September 22, 2014 stating their concurrence with the TDM and finding that it “conforms to the state-of-practice in travel demand modeling; meets overall traffic assignment validation standards suggested by FHWA and Caltrans; and is an appropriate tool for the County’s long range planning purposes." (See Supporting Documents for Caltrans and SACOG letters.)

Upon completion of the TDM, several peer reviews were completed by Kittelson and Associates Inc., Caltrans, and SACOG. El Dorado County staff met several times with both SACOG and Caltrans during the development of the new TDM, and continue to meet with both agencies in the ongoing effort of keeping the model up-to-date.

The new TDM is an essential tool for implementing the General Plan goals and policies, updating the Zoning Ordinance, planning of new roadways for the Capital Improvement Program (CIP), and updating Traffic Impact Mitigation (TIM) Fees. The TDM will help guide the County through the next twenty-five years of land use planning. The new model will be not only be used by the County but also by private companies and public agencies such as Caltrans. The County intends to keep the model current, updating it as needed to incorporate new development.  The latest update was completed in August 2018.

For a comprehensive list of Items presented to the Board on the TDM, click on the Board of Supervisors Agenda Items tab.

​Board of Supervisor Agenda Items

Please note: These agenda items may not reflect the most current information and are subject to change. For the latest information on agenda items related to this project, refer to the County online agenda calendar: https://eldorado.legistar.com


DateItemFile IDVer.Description
6/17/2014 3413-12186Community Development Agency, Long Range Planning, providing the Board with a Long Range Planning update including the Land Use Policy Programmatic Update (LUPPU).
4/15/2014 1813-12185Community Development Agency, Long Range Planning, providing the Board with a Long Range Planning update including the Land Use Policy Programmatic Update (LUPPU).
4/8/2014 1214-02454Community Development Agency, Long Range Planning, recommending the Board approve the Scenario 3 growth forecast as the starting point for initiating the Major Five-Year Capital Improvement Program and Traffic Impact Mitigation Fee updates.
3/18/2014 611-14415 Community Development Agency, Long Range Planning, recommending the Board approve and authorize the Purchasing Agent to sign Amendment III to Agreement for Services No. 396-S1211 with Kimley-Horn and Associates, Inc. for Travel Demand Model creation and update services, expanding the scope of work and increasing the not-to-exceed amount of the Agreement by $16,000 for a new not-to-exceed total amount of $501,477, and extending the term of the Agreement to December 31, 2015, contingent upon review and approval of the Amendment by County Counsel and Risk Management. FUNDING: The total contract is funded by a combination of Traffic Impact Mitigation Fees, Road Fund, and General Fund. Amendment III is specifically funded by the General Fund (no Federal Funding).
3/4/2014 2013-12184 Community Development Agency, Long Range Planning, providing the Board with a Long Range Planning update including the Land Use Policy Programmatic Update (LUPPU).
2/24/2014 114-02451 Community Development Agency, Long Range Planning, recommending the Board consider the following: 1) Receive information on El Dorado County’s General Plan Travel Demand Model; 2) Direct staff to proceed with one of the growth forecast scenarios as the starting point for initiating the Major five-Year CIP and TIM Fee updates; and 3) Receive information on how the County implements General Plan Policy TC-Xa (Measure Y) and associated General Plan Policies TC-Xb through TC-Xi.
1/28/2014 613-12183 Community Development Agency, Long Range Planning, providing the Board with a Long Range Planning update including the Land Use Policy Programmatic Update (LUPPU).
12/3/2013 3213-12182 Community Development Agency, Long Range Planning Division, providing the Board with a Long Range Planning update including the Land Use Policy Programmatic Update (LUPPU).
10/29/2013 1913-12181 Community Development Agency, Long Range Planning, providing the Board with a Long Range Planning update including the Land Use Policy Programmatic Update (LUPPU).
10/22/2013 911-14414Chief Administrative Office recommending the Board authorize the Purchasing Agent to execute Amendment II to Agreement for Services No. 396-S1211 with Kimley-Horn and Associates, Inc. revising the scope of services to add two additional tasks under Component 2 - Environmental Impact Analysis for Targeted General Plan Amendment (TGPA) and Zoning Ordinance Update and adding one additional task under Component 4 - Rural Area Land Use Forecasting and Iterative Analysis, increasing the contract amount by $33,940 for a total contract amount of $485,477.50, and extending the term through July 31, 2014, contingent upon review and approval of the Amendment by County Counsel and Risk Management. FUNDING: The total contract is funded by a combination of Traffic Impact Mitigation (TIM) Fees, Road Fund, and General Fund. Amendment II is specifically funded by General Fund.
9/30/2013 213-12191Community Development Agency, Long Range Planning Division recommending the Board receive additional information as a follow up to the presentation provided by the Measure Y Committee on August 26, 2013. The discussion provides information on the following topics: 1) Level of Service on State Highway 50 and Measure Y Interpretation; 2) Land Development Projections; 3) Land Use Policy Programmatic Update (LUPPU); 4) Traffic Impact Mitigation (TIM) Fee Program; 5) Next Steps.
7/30/2013 2913-09241 Community Development Agency (CDA) Long Range Planning Division presenting a workshop to begin the preparation of the 2014 Capital Improvement Plan (CIP), and requesting direction on the Board’s preferred growth projection option for the CIP and Traffic Impact Mitigation Fee (TIM) Fee Program updates.
3/25/2013 512-04756 Chief Administrative Office providing a presentation on the Travel Demand Model.
3/5/2013 711-11413 Chief Administrative Office recommending the Board authorize the Purchasing Agent to execute Amendment I to Agreement for Services No. 396-S1211 with Kimley-Horn and Associates, Inc., revising the scope of services to add Component 4 which includes Task 4.1 - Rural Area Land Use Forecast, Optional Task 4.2 - Land Use Forecast Revision and Model Analysis, Optional Task 4.3 - Meetings and Documentation, and Optional task 4.4 - Additional Presentations, and increasing the contract amount by $72,042.50 for a total contract amount of $451,537.50.
2/26/2013 2312-026713 Chief Administrative Office providing an update on the Land Use Policy Programmatic Update (LUPPU) process.
1/28/2013 312-15781 Department of Transportation recommending the Board receive information regarding the Capital Improvement Program, the Traffic Impact Mitigation Fee Program, and the Travel Demand Model.
12/4/2012 4012-026711 Chief Administrative Office presenting update on the Land Use Policy Programmatic Update (LUPPU).
10/30/2012 3412-026710 Chief Administrative Office presenting update on the Land Use Policy Programmatic Update (LUPPU).
9/25/2012 4312-04755 Chief Administrative Office recommending the Board provide direction on roadway parameters to be analyzed with the Travel Demand Model.
7/24/2012 1912-04754 Chief Administrative Office recommending the Board provide comment and direction on the Roadway Network Map and Traffic Analysis Zone Map (Attachments 3A & 3B) for use in updating the El Dorado County Travel Demand Model.
6/26/2012 4612-04753 Chief Administrative Office recommending the Board review and comment on the Roadway Network Map and Traffic Analysis Zone Map (Attachments 3A & 3B) for use in updating the El Dorado County Travel Demand Model.
5/1/2012 3912-04752 Chief Administrative Office recommending the Board review and comment on the Travel Demand Model Update major assumptions as shown in Attachment A that will be used to establish Achievable Development, 2025 No-Project, and 2035 Project/No Project land use forecasts for use in updating the El Dorado County Travel Demand Model as described in the Kimley-Horn & Associates, Inc.’s Technical Memorandum No. 10: Land Use Assumptions. (Cont'd 4/16/12, Item 2)
4/16/2012 212-04751 Chief Administrative Office recommending the Board review and comment on the Traffic Model Update major assumptions as shown in Attachment A that will be used to establish Achievable Development, 2025 No-Project, and 2035 Project/No Project land use forecasts for use in updating the El Dorado County Travel Demand Model as described in the Kimley-Horn & Associates, Inc.’s Technical Memorandum #10: Land Use Assumptions.
3/27/2012 2112-02672 Chief Administrative update of the Land Use Policy Programmatic Update (LUPPU).
2/27/2012 212-02671 Chief Administrative Office providing a status report and requesting discussion and direction on the Land Use Policy Programmatic Update (LUPPU) including the following:1) Targeted General Plan Amendment; 2) Housing Element Amendment; 3) Zoning Ordinance Update; and 4) Travel Demand Model Update.
1/24/2012 3611-14412 Chief Administrative Office recommending the Board authorize the Purchasing Agent to execute Agreement 396-S1211 with Kimley-Horn and Associates, Inc. to update the County’s current Traffic Model for an amount not to exceed $379,495 for a two year term, upon review and approval by County Counsel and Risk Management.
12/19/2011 411-14411 Department of Transportation recommending the Board receive an update and provide direction on the Traffic Model Update.

​Supporting Documents

Travel Demand Model Assumptions, Methodology, and Reports

Other Related Documents

If you have questions on the Travel Demand Model project, please contact:

Natalie Porter
Senior Civil Engineer
natalie.porter@edcgov.us
(530) 621-5442 Direct
(530) 621-4650 Main






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