Rethinking how we build so people can drive less: LOS to play more limited role in planning, to reduce VMT

SB 743 Implementation

Caltrans October 6, 2020 TAF/TAC webinar recording and TAF/TAC power point (PDF) is now available!  The webinar highlights the TAF and TAC guidance documents—available below.  Caltrans followed up the webinar with recorded answers to remaining questions.

New guidance documents are available for projects on the State Highway System (SHS):

Q&A: Caltrans TAF and TAC (PDF) document was compiled based upon input received during the draft documents’ informal review.  A final version is now posted.

The Expert Panel Report (PDF) informed the TAF’s induced travel methodology

Caltrans Policy Memo (PDF) communicates to Caltrans staff regarding analysis of transportation impacts under CEQA for projects on the SHS

“While CEQA does not require perfection,” says the document,

It is important to make a reasonably accurate estimate of transportation projects’ effects on vehicle travel in order to make reasonably accurate estimates of [greenhouse gas] emissions, air quality emissions, energy impacts, and noise impacts.

Helpfully, the guidance includes a list differentiating those projects that are likely to lead to a “measurable and substantial increase in vehicle travel,” and those that are not. Those that do are capacity-expanding projects such as

Addition of through lanes on existing or new highways, including general purpose lanes, HOV lanes, peak period lanes, auxiliary lanes, or lanes through grade-separated interchanges.

The new rules take effect immediately as advisory, but by June 2020 they will apply to all new environmental analyses. In the meantime many municipalities haven’t waited. San Jose, Pasadena, San Francisco, Oakland, and others have already adopted the new vehicle miles traveled metric.

By Chris McCahill, SSTI

new survey of planning officials in California finds that most are embracing the shift from highway level of service to vehicle miles traveled for evaluating the environmental impacts of new development projects. While some are ditching LOS altogether, however, many still rely on it to measure traffic impacts.

This unprecedented change in how environmental impacts are measured was prompted by California’s SB 743, which passed in 2013 and acknowledges the adverse effects that LOS considerations can have on multimodal access and infill development. All jurisdictions have to transition by July of 2020 but Pasadena and others have already made the necessary changes.

The new survey includes 77 high-level planning staff from cities and counties across California as they make the transition. While many are still finalizing their new rules, almost all of them (96 percent) feel VMT is the most appropriate metric or useful to some extent. Four times as many respondents (16 percent) find LOS inappropriate for measuring environmental impacts, compared to VMT (4 percent).

Few jurisdictions will use VMT outside of the environmental review process, according to the survey, but almost half will continue using LOS to determine traffic impact fees. Only four percent said they would use LOS exclusively and 40 percent will not use LOS at all. For its part, Caltrans is currently planning how to move from LOS to VMT for evaluating the environmental impacts of transportation projects but it will have more time to make the change.

Chris McCahill is the Deputy Director at SSTI.


Streetsblog, Nov 25 2019

Caltrans Will Account for New Driving Produced by its Transportation Projects

A “profound change” in how transportation impacts are accounted for is coming, in line with efforts to reduce greenhouse gas emissions and driving and increase biking, walking, and transit trips

Caltrans hosted a webinar recently to discuss changes it will be adopting soon in the way the department measures, analyzes, and mitigates for the environmental impacts of transportation projects on the state highway system.

The department acknowledges that its current practices have not solved urban congestion and instead have led to more driving, more emissions, and unsafe conditions for people who don’t drive.

The policy changes are in response to S.B. 743, which was passed in 2013 but has taken years to develop into practice. That law required the state to find a better way to measure the environmental impacts of transportation than by measuring vehicle delay. Until recently, agencies accounted for environmental impacts by analyzing Level of Service, or LOS, which looks only at how much delay a project would cause vehicle traffic. There was no analysis of how much new driving might occur.

To address the resulting auto delay, projects were required to widen roads and intersections to allow more vehicles through faster. Those mitigations made driving easier and faster, while the experience and safety of other road users was ignored.

Result: more driving. “This widespread response to new capacity is the reason we have been unable to reduce congestion in urban areas for more than a short time,” said Chris Schmidt, who manages Caltrans’ S.B. 743 program and led the recent webinar.

Two kinds of projects are subject to new rules under S.B. 743Land use projects, which Caltrans weighs in on if they affect the state highway system, and transportation projects, for which Caltrans serves as the lead agency if they are on state highways.

Land use projects will be required to use the new measure, vehicle miles traveled, starting next July. Some cities, notably Los Angeles, Pasadena, San Francisco, and San Jose, have already adopted the measure in their planning practices.

The Governor’s Office of Planning and Research (OPR), which developed the guidelines for S.B. 743, gave lead agencies some leeway on highway capacity projects, saying they “could choose the most appropriate” way to measure environmental impacts.

Caltrans says it has decided that vehicle miles traveled (VMT) is generally the most appropriate measure to assess the impacts of transportation projects.

“These changes are profound, and will challenge the state of practice for all of us,” said Schmidt to the more than 400 practitioners–city planners and engineers, Caltrans staff, and consultants–who were listening to the webinar.

Until recently, Caltrans has resisted acknowledging the concept of induced demand, which shows that building new roads and widening existing ones does not reduce congestion but in the long term–sometimes even in the short term–just adds more cars to the system.

California cities are beginning to understand that there is no room for more cars in the system. And state agencies are starting to acknowledge that reducing greenhouse gas emissions will require reduced driving, not just shifting to renewable energy. But as long as agencies continue to try to solve congestion by adding roadway capacity, driving will increase.

Note that not every last transportation project is subject to Caltrans’ new rule. For example, most of the projects in the State Highway Operation and Protection Program will not be subject to it, because most of them focus on maintenance and rehabilitation, rather than increasing capacity.

Caltrans is still working out the details of these new policies, including when they will take effect. While the land use projects must begin using the new measure by July, no date has yet been set for transportation projects. It is a cause for concern among planners and agencies who are planning future projects, a process that can take years. According to Schmidt, “Caltrans has been working on the best date to begin, and intends to have further discussions to set a date in the near future.”

Another key aspect that will require more work is the question of mitigation. Under the California Environmental Quality Act, agencies must analyze environmental impacts and find a way to mitigate what they can. As pointed out above, under the old system that mitigation took the form of wider and faster roads, to avoid delay. But VMT is harder to mitigate.

Schmidt mentioned some potential measures, including supporting people who shift from cars to other modes like biking, walking, and transit; supporting higher occupancy vehicles; mitigation banks, which could create a way to trade mitigation offsets; and transportation demand management policies. “Caltrans is committed to developing robust mitigation strategies,” said Schmidt, and recognizes that it will need partners in that effort.

It’s important to note that these measures are key to reaching state climate and health goals. Unless they truly are robust, and include strategies like parking and congestion pricing, automatically including complete streets elements in every project, planning and building better biking and walking infrastructure, and investing in transit operations and service improvements, they will just be a waste of time.

OPR has done extensive work on the question of mitigations — a lot of research is collected together on its website here — and Caltrans says it is committed to using the OPR guidance in its own documents.

The department is continuing to develop guidance on mitigation as well as on how to conduct the transportation analysis, on methods for calculating vehicle miles traveled and induced travel demand, on determination of impacts under CEQA, and on measuring and determining greenhouse gas emissions.

Draft documents should be available in early 2020, with a four-week comment period. More webinars are planned during that time; more information here, as it becomes available. Caltrans plans to release its final guidance in spring or summer of 2020.


About SB 743

SB 743 was signed in 2013, with the intent to “more appropriately balance the needs of congestion management with statewide goals related to infill development, promotion of public health through active transportation, and reduction of greenhouse gas emissions.” When implemented, “traffic congestion shall not be considered a significant impact on the environment” within California Environmental Quality Act (CEQA) transportation analysis.

SB 743 requires the Governor’s Office of Planning and Research (OPR) to identify new metrics for identifying and mitigating transportation impacts within CEQA. For land use projects, OPR identified Vehicle Miles Traveled (VMT) per capita, VMT per employee, and net VMT as new metrics for transportation analysis. For transportation projects, lead agencies for roadway capacity projects have discretion, consistent with CEQA and planning requirements, to choose which metric to use to evaluate transportation impacts.

Regulatory changes to the CEQA Guidelines that implement SB 743 were approved on December 28, 2018.  OPR released a December 2018 Technical Advisory that contains recommendations regarding assessment of VMT, thresholds of significance, and mitigation measures.  Statewide implementation occurred on July 1, 2020.

Caltrans SB 743 Implementation

SB 743 affects important parts of Caltrans work:

  • Review of local land use projects’ potential impact to the State Highway System through our Local Development-Intergovernmental Review program
  • Transportation analysis including induced vehicle travel demand analysis for projects on the State Highway System.

Caltrans is developing guidance documents to implement vehicle miles traveled in projects on the State Highway System, and our review of local development projects. We are evolving our transportation analysis to be more multimodal—part of implementing our Strategic Management Plan 2015-2020.

Implementation Documents

Caltrans SB 743 implementation documents will be posted as draft and final documents are completed. Contact to join Caltrans SB 743 listserv and receive notifications when draft and final documents are posted.

Implementation Webinars

Caltrans discusses the guidance documents and SB 743 implementation work in a series of webinars.

Projects on the State Highway System

Caltrans has chosen to use VMT as the CEQA transportation metric for projects on the state highway system. Caltrans is working with partners to develop guidance that provides:

  • Process for a prospective phase‐in that does not require any re‐analysis and strives to ensure no delay for current projects – such as the programmed SB 1 and upcoming Local Measure projects.
  • Clarification of the type of projects requiring detailed VMT analysis.
  • Clarification on acceptable mitigation such as, but not limited to, VMT banking, regional investment program, and exchange mechanisms.
  • Quantification tools for VMT, including induced travel and methodology for VMT based analyses.
  • Clarification on safety and operations analysis, including tools to assess safety impacts, which could include use of LOS as an input for the safety analysis.

Caltrans Local Development-Intergovernmental Review (LD-IGR)

Mitigating Vehicle Miles Traveled

Strategies that support mode shift, higher vehicle occupancy, shorter average vehicle trips, and transportation demand management can mitigate VMT. VMT impacts should be mitigated to the maximum extent possible. Current mitigation resources are highlighted in SB 743: Mitigation and VMT Reduction (PDF).

Fact Sheets and Video


Caltrans’ California Statewide Travel Demand Model (CSTDM) VMT data is available for use when calculating residential and office projects’ VMT. Contact if you have questions about the CSTDM data.

Research Efforts

Caltrans Division of Research and Innovation (DRISI) supports SB 743-related research efforts.

  • Transportation Research Board”In 2015, Caltrans sponsored a review of applicable induced vehicle travel research that could inform transportation analysis guidance in response to new laws in California such as Senate Bill 743, which prohibits the use of vehicle level of service and similar measures as the sole basis for determining significant transportation impacts under the California Environmental Quality Act.” (Source: Transportation Research Board). Marc Birnbaum, Caltrans Traffic Operations (retired), co-authored the Transportation Research Board peer-reviewed paper: “Closing the Induced Vehicle Travel Gap Between Research and Practice” – January 1, 2017
  • U.S. DOT Volpe Center“Evolving Use of Level of Service Metrics in Transportation Analysis” includes a California case study on SB 743.
  • U.S. DOT Federal Highway Administration November 30, 2017 Webinar highlights the case study; click on the California 0:31:23 link.

Additional Resources

  • The San Diego Section of the Institute of Transportation Engineers (ITE) has prepared updated regional Transportation Impact Study Guidelines to incorporate SB 743. The May 2019 document titled “Guidelines for Transportation Impact Studies in the San Diego Region” is available on ITE San Diego’s TCM Task Force page.
  • SB 743 Case Studies: The Urban Sustainability Accelerator at Portland State University created five case studies on how to apply the vehicle miles traveled metric to a highway project and three land use projects.
  • Evaluation of Sketch-Level Vehicle Miles Traveled (VMT) Quantification Tools: National Center for Sustainable Transportation “researchers compare and evaluate VMT estimation tools across a sample of land use projects. They compare the results from different tools for each project, consider the applicability of methods in particular contexts and for different types of projects, and assess data needs, relative ease of use, and other practical considerations.” The research is not done within a CEQA context, but it is interesting to review the use of the VMT estimation tools.

SB 743 Contact

For more information on Caltrans SB 743 implementation efforts or to receive updates on Caltrans SB 743 work via our listserv, contact