Frequently Asked Questions



What is the purpose of this project?

The Land Use Impact Analysis Program Policy is a component of the San Mateo County Congestion Management Program (CMP). The policy provides guidelines for analyzing the impact of land use decisions made by local municipalities in San Mateo County. The purpose of the policy is to preserve acceptable performance on the countywide CMP network, and to establish community standards for consistent, system-wide review of development-related transportation impacts. For purposes of this project, this policy is rebranded as the Transportation Demand Management (TDM) Policy. 

California Government Code Section 65089 requires that Congestion Management Agencies, such as C/CAG, include a TDM Policy in their regional (county) CMPs and, moreover, measure the impact of local land use decisions on the regional transportation network. The TDM Policy is intended to satisfy this law and proactively mitigate degradation of the CMP Network performance. TDM is also a crucial tool among an array of methods to address State and regional transportation, land use, environmental, and general planning policies.

How will this TDM Policy Update affect local jurisdiction development review procedure?

Local control over development review does not change as a result of the TDM Policy Update. What does change is the introduction of an additional checklist that applicants must submit to local municipalities as part of their development application – provided their project estimates at least 100 weekday ADT. This new, required TDM Checklist is intended to document how the project will mitigate adverse development impacts on the CMP network. 

This TDM Policy Update addresses only projects that will generate at least 100 average daily trips. Further detail regarding this threshold is provided in the publicly available Policy Approach document and in the companion Implementation Guide (see

How does this TDM Policy relate to the proposed C/CAG VMT Estimation Tool?

The TDM Policy and the C/CAG VMT Tool are separate, but complementary efforts. The TDM Policy is focused on mitigating development-related travel demand on the CMP Network using the ADT metric whereas the VMT Tool will assist local agencies in their CEQA analysis of local development-related transportation impacts by providing, among other things, VMT reduction estimations from the various TDM measures selected to address CEQA related impacts. 

Has C/CAG assessed the interactions between the TDM Policy and other state legislation to streamline the provision of housing (e.g., SB 35, SB 330)? What should local municipalities advise an applicant in these situations?

It is not anticipated that the TDM Checklist would conflict with nor complicate the processes set forth under SB 35, SB 330, et al. In fact, as required by the State Permit Streamlining Act, it is foreseeable that a local municipality would include the proposed TDM Checklist on the list of required application materials given to a project applicant. The TDM Checklist is a spreadsheet-based scoring rubric that involves simple, additive math designed to set the project applicant/developer up for success in achieving the stated goal of 25- 35% single occupant vehicle trip reduction, depending on the project size/location. The expectation is that it be folded into the local development review process – completed and delivered by the applicant at the outset of their project development submittal. It is intended that the local municipality would verify this submitted Checklist in tandem with all other local project submittal requirements. Therefore, since the TDM Checklist is expected to be included in the preliminary application submitted at the outset of development review, it would not create additional, undue burden. 

Moreover, local municipalities should make project applicants aware of the C/CAG TDM Land Use Policy Update in pre-application meetings and materials (online, permitting handbooks, guidance sheets, etc.) as necessary.

If a lead agency determines a local project would have less-than-significant transportation impacts under CEQA, is a C/CAG TDM Checklist still required to be submitted?

Yes, a project with less-than-significant transportation impacts under CEQA is still subject to C/CAG TDM Policy if said project estimates 100 or more ADT. To confirm, this would also apply for local projects that are deemed to have significant transportation impacts under CEQA as well. 

The reason for this is that CEQA analysis accounts for VMT impacts, as required by SB 743, however the C/CAG TDM Policy accounts for ADT impacts on the CMP Network. Thus, CEQA analysis alone does not sufficiently account for potential transportation-related project impacts under the TDM Policy Update.

Are developments required to comply with the TDM checklist if they have submitted an SB 330 or preliminary application or SB 35 application prior to January 1, 2022?

SB 330 does create a process for filing of a preliminary application, which, if it contains all the information required by law, limits application of ordinances, policies, and standards to those that were in effect at the time the preliminary application was submitted. Accordingly, the policy would not apply to these SB 330 vested projects due to that provision, presuming they had completed the preliminary application process prior to Jan 1, 2022, and that they otherwise follow through on the development application process to maintain their vesting status by filing a full application within 180 days and following any other requirements of SB330.

SB 35 was revised by AB 168 in 2020 to add a similar vesting component. SB 35 applicants can now lock in the objective zoning, subdivision, and other standards that can be applied to those in effect at the applicant submits a “notice of intent” to submit a SB 35 application. Gov. Code § 65913.4(a)(5). As a result, the updated TDM policy would not apply to such projects filed before January 1, 2022.

Note: These examples highlight the need for local jurisdictions to reference the updated TDM Policy requirements in their local development review checklist criteria as soon as possible.

Cities are required to comply with the CMP. There needs to be the connection that recognizes that the TDM Policy is included as part of compliance with CMP requirements, and this flows to local development standards.

Can you confirm that only projects submitted after Jan 1, 2022, are subject to the TDM policy and checklist?

Only project applications that were “deemed complete” prior to Jan 1, 2022, are not subject to the policy.

Who are the best contacts at and C/CAG to respond to applicant questions on the policy/checklist?


How would the new policy apply to pipeline projects, and projects which were analyzed under a Program EIR that was certified prior to the new state requirements for VMT analysis and this C/CAG policy? 

This updated TDM Land Use Policy will take effect January 1, 2022 (see also questions #2 & 3, above). Pipeline projects analyzed under a program EIR that do not have an application that has been deemed complete by the local municipality prior to the effective date of the updated TDM Policy (January 1, 2022), would be subject to these requirements. Supporting informational materials are available at the dedicated C/CAG TDM web page, including TDM scoring checklists and TDM monitoring documents.

Has C/CAG assessed equity impacts as part of the TDM policy and implementation approach to these requirements? E.g,. racial equity toolkit approach to the policy and implementation program and how that might impact development or programs in communities of color, low-income communities? We want to ensure that our most vulnerable communities would benefit from this policy.

C/CAG has been working with a number of agencies on the US 101 Mobility Action Plan (101 MAP) to develop non-infrastructure strategies to increase throughput in the corridor, and one of those strategies is to develop a countywide TDM plan.  The MAP also identifies equity actions that can accompany each strategy and has identified two equity actions related to the recommended development of countywide TDM developer requirements: “build requirements that provide transportation solutions 24 hours a day” and “Encourage subsidized transit passes and memberships for new mobility services for affordable housing residents.”  

In developing this TDM Land Use Policy Update and the associated trip reduction measures that promote a wide variety of alternative travel modes, C/CAG included ADT as the standard metric to address all trips rather than just peak hour trips and have included subsidized transit passes as a required measure throughout. The C/CAG Land Use Policy Update is aimed at a more regional and consistent approach to TDM Program requirements and measures. The C/CAG Land Use Policy Update TDM Checklist measures are accessible to all individuals regardless of income.

Why are single family homes exempt?

It is difficult to put together a TDM program for single family homes. CEQA requirements would be more applicable to address traffic-related impacts of single family homes and it is unlikely there will be many more single family subdivisions built in the County.

Is there a definition of “new development project”? For example, would an addition or change in land use/business at an existing structure trigger TDM policy review or TDM policy compliance?

The policy does not include a specific definition but is generally understood to be either new construction, conversion or intensification of use that would increase the number of vehicle trips to or from the site. The policy would only affect new development projects that are expected to generate 100 or more ADT over existing conditions. (It is anticipated that this definition will be more clearly addressed in a future near-term policy update)

With regard to exemption, do the guidelines define single family resident or multi-family residential? We have developers who want to market their projects as “attached single family” homes.

The TDM Policy does not include a specific definition; however, our intention was traditional detached single-family homes on individual lots. It is anticipated that this will be more clearly addressed in a future near-term policy update.

Who is responsible for asking for an exemption?

The applicant would likely request an exemption to the TDM requirements based on a TIA or other documented evidence showing the project would generate <100 ADT. The local jurisdiction would be responsible for verifying validity of ADT.

Please clarify the terms “complete application” and “complete project”?

“Complete application” is a term in planning law that is established for permit streamlining purposes. A project application is officially “deemed complete” by a planning agency when the applicant has submitted all the required application materials to allow the project entitlement process to proceed. This TDM Policy applies only to project applications that are deemed complete on or after Jan. 1, 2022.

“Complete project” refers to when the actual project construction has been completed and has been issued a Certificate of Occupancy (C of O). This is the point where the local jurisdiction will confirm that any site design features that are included in the TDM Checklist for the project (ex. shower/locker facilities, secure bicycle storage, etc.) have been completed. It is also the baseline date for subsequent monitoring and reporting cycles.

It is expected that local jurisdictions will condition project approval on compliance with the TDM Policy. Can C/CAG suggest standard Condition of Approval language?

The following is provided as suggested language: 

“The property owner shall ensure compliance with the San Mateo County Congestion Management Program Land Use Implementation Policy (C/CAG TDM Policy). Specifically, the property owner shall ensure that the measures identified in the approved C/CAG TDM Checklist appended to this application are implemented over the life of the project, and that the property owner and tenants acknowledge the requirement to participate in the periodic monitoring and reporting requirements identified in the C/CAG TDM Policy. Accordingly, it is recommended that the property owner and/or developer clearly identify these TDM provisions and responsibilities in any sales and/or lease or sublease transactions.”

(The main points are that the property owner is responsible to ensure the measures are implemented over the life of the project and that the tenants will comply with the monitoring and reporting components of the policy. It’s very important that these provisions be written into sales and lease agreements since most projects do not remain owner occupied.)


Why is ADT the recommended traffic mitigation metric?

The Average Daily Trip (ADT) travel demand metric captures broader daily travel demand to and from site(s), rather than trying to shift marginal demand from narrower off-peak or peak hour timeframes during the day. Based on available academic and technical literature, as well as local, regional, state, and national case studies, there is ample support for utilizing this metric in lieu of other traditional metrics, such as Level of Service (LOS). 

Why isn’t VMT the recommended traffic mitigation metric, now that SB 743 is in force as State law (as of July 1, 2020)?

As written, SB 743 requires a lead agency to utilize the VMT metric when conducting transportation analysis for projects subject to the California Environmental Quality Act (CEQA). Accordingly, if said agency makes findings of significant transportation impact, then mitigation must address VMT as well. 

By comparison, congestion management agencies, such as C/CAG, and their respective congestion management programs (CMPs) are bound to State law under California Government Code sections 65088 – 65089.10. Under this auspice, congestion management agencies (CMAs) are required to mitigate trips using LOS on their CMP Network. Supplemental to this LOS requirement, per feedback item #7 above, ADT has been adopted for this TDM Policy Update as the primary traffic mitigation metric because it captures both peak and off-peak travel demand on the CMP Network. 

This TDM Policy does not supersede SB 743 – projects subject to CEQA review must adhere to State environmental law. 

When making a determination as to whether a development application qualifies for C/CAG TDM mitigation, do both the minimum ADT and square footage thresholds apply? Or just one or the other?

The determination as to whether a project is subject to the C/CAG TDM Policy Update will be dependent on project ADT. The minimum threshold is 100 ADT or more; anything less is exempt (i.e., < 99 ADT). 

Relevant square footages cited in project documents are purely for reference. These are approximations that assume a linear relationship between project size relative to travel demand. 

If the TDM threshold is in terms of trip reduction percentage (%), what is the purpose of estimated SOV percentage (%) mitigation for each measure?

(The SOV percentage mitigation for each TDM measure was studied and applied during the TDM Policy Update process. Technical justification for this background metric is described in the Policy Approach, Appendix A).

In summary, the trip reduction percentage threshold for each land use category represents a target reduction of single-occupant vehicle (SOV) trips. These types of trips are the most common in San Mateo County which, according to the SMC Congestion Management Program account for nearly 70% of daily commute trips. SOV trips are well-documented as being relatively inefficient compared to other transport modes, such as carpooling and bus and rail transit, which carry significantly greater passengers per vehicle over a finite mobility network. 

Therefore, the TDM Policy aims to reduce (mitigate) SOV trips by encouraging trips by other modes. Even if those shifts happen infrequently, such as once per week, the aggregate network effect can be significant. 

Details of this concept are explained in the Policy Approach document, which clarifies that the trip reduction ratio is the primary metric to evaluate project TDM performance. The SOV mode share reduction ratio is a complementary metric that, when considered alongside the primary metric, accounts for the overall estimated trip reduction potential; this accounting is also subsequently reflected in the weighted point value featured in the TDM Checklist and Scoring Sheet. 

Why are some measures “Required” while others are “Additional Recommended”?

Priority is placed on measures consistent with C/CAG and regional transportation goals and policies. The categorical distinction between measures is also influenced by stakeholder feedback provided during the Policy Update process, including from local planners and developers, regarding feasibility and assigned trip reduction ratios/scoring. 

Importantly, the C/CAG TDM Implementation Toolkit instructs that the TDM Checklist applies to projects on a case-by-case basis, and therefore not all Required measures may be feasible for a given site. If this situation transpires, then it is recommended the local municipality collaborate with the project applicant to document the reasons for this incompatibility and identify alternative solutions to mitigate SOV trips related to the project. 

How does the TDM Checklist address projects with multiple phases, which may be years apart?

Phases are typically identified at outset of development review. Therefore, Conditions of Approval (COAs) can be placed on entitlements (i.e., permit approvals) for each phase. In turn, COAs run with the land and are thus passed down regardless of ownership. 

It is expected that local municipalities will make TDM measures selected in the TDM Checklist COAs, which then become contractually enforceable. 

What is the “TDM fee” mentioned in the program and who is responsible for determining the amount?

This comment refers to an Additional Recommended TDM measure featured in the Checklist called “Developer TDM Fee/TDM Fund”. The applicable fee is intended to be applied by the local municipality according to its approved development fee schedule, or otherwise negotiated as part of a development agreement according to applicable local laws and provisions. 

C/CAG is not proposing to set a comprehensive fee structure as part of this TDM Policy update.

In conclusion, these fees are subject to local municipality discretion and/or ordinance. 

While the Checklist scoring system provides an easy format, there also needs to be flexibility built in to provide other options to meet the goals.

The TDM Checklist relies on trip reduction ratios, which are the estimated percentage of SOV trips that could be reduced by implementing a given TDM measure. The TDM Checklist states in its instructions section that a municipality may, in coordination with the development applicant, substitute certain TDM measures that are deemed infeasible (i.e., cost-prohibitive or otherwise) with other strategies that are likely to produce comparable trip reduction impacts. In such case, clear and sufficient documentation should be produced regarding the rationale for said changes. 

Will C/CAG provide resources to work with applicants to discuss these options, especially where the local municipalities do not have the expertise? can provide complimentary TDM guidance to local municipalities and project applicants. This assistance will be policy-oriented (in terms of step-by-step process) rather than technical decisions related to TDM strategy. 

The revised requirements will necessitate additional review by staff that may not have experience evaluating appropriateness of TDM strategies for a certain project – or advising on such. Could staff refer applicants directly to to work with applicants on TDM strategies and to iron out any necessary processes for ongoing monitoring? For example, how would Planner’s assess whether an applicant’s plan for “providing active transportation subsidies” is appropriate?

The intent of the TDM Checklist is not to have cities make a judgment on the efficacy of a TDM measure unless an applicant chooses to substitute something outside of the recommended measures. Utilizing the Checklist, a project applicant simply needs to select the Required TDM measures, apply the associated trip reduction percentage, and in doing so is being set up for success for the targeted single occupant trip reduction target. That said, is available as a resource for applicants to discuss implementation of TDM plans, including assistance in determining which of the “recommended” measures/programs might be more beneficial for their specific workplace, providing training for property managers/TDM Coordinators, and otherwise helping them promote their TDM programs. 

Can local municipalities be exempted from the C/CAG TDM Policy, including requirement to submit a TDM Checklist for new development projects with > 100 ADT?

Yes, under certain conditions. If a local municipality has adopted local policies that are at least as stringent as the C/CAG TDM Policy with respect to efforts to mitigate adverse impacts on the Congestion Management Program (CMP) network, they may submit a formal request for exemption to C/CAG along with clear documentation for a determination. 

Once exempt, however, the municipality must still notify C/CAG in writing when a new development project estimates more than 100 ADT is submitted for review. More details are provided in the Implementation GuideMore details are provided in the Implementation Guide

How does the TDM Policy account for trip reduction at Mixed-Use development projects? Which TDM Checklist would apply to a project with multiple land uses on site?

Mixed-Use development projects must account for cumulative ADT from all land uses at the project site. To select the TDM Checklist with the corresponding land use that is most appropriate to evaluate a Mixed-Use development, the project applicant choose the Checklist that reflects the site land use estimated to generate the most daily trips. By this rationale, the selected TDM Checklist will mitigate impacts stemming from the most trip-intensive land use documented at the Mixed-Use site. For example, if a Mixed-Use project will cumulatively generate over 500 ADT and a Non-Residential Office land use at the site will generate most of those trips, then the applicant should complete and submit the Large Non-Residential (Office, Industrial, Institutional) TDM Checklist, but the measures will apply to all site uses. 

The TDM measures pertaining to “large” projects across all land use categories are also comparable. The same is true of “small” projects across land use categories as well. So, selecting the Checklist that most closely relates to the predominant land use, in terms of trip generation, is a means to emphasize mitigation of the most intensive use on-site. This approach does not exclude nor diminish the effectiveness of TDM for the other site uses because the measures are to be applied to, and thusly affect, the project as a whole. 

Will the TDM Checklist (i.e., TDM measures and trip reduction ratios) be reviewed and revised at a regular intervals? Will these updates be incorporated into the Countywide VMT tool?

C/CAG will coordinate with the working group managing the VMT Estimation Tool for San Mateo County to ensure the C/CAG TDM Land Use Policy Checklist updates are congruent with the intent of VMT goals. The TDM Policy and the C/CAG VMT Estimation Tool are distinct, but complementary efforts. The TDM Policy is focused on reducing vehicle travel on the Congestion Management Program (CMP) Network using the ADT metric and a points-based TDM reduction analysis, whereas, to help with a CEQA analysis, the VMT Estimation Tool is used to conduct baseline VMT screening and VMT reduction analysis for specific land use projects. The VMT Estimation Tool relies on empirical data collected from the VTA/CCAG travel model and CAPCOA VMT reduction research, which is typically updated every 5 to 10 years. Travel models undergo moderate to major updates every 5 to 10 years to remain calibrated to local conditions. 

The VMT Estimation Tool addresses TDM measures in two ways.  First, the VMT Estimation Tool includes built-in TDM measures, such as assumptions of shuttle service. Second, the VMT Estimation Tool includes specific TDM measures, many of which are included in the C/CAG TDM Measure Checklist.  The VMT Estimation Tool will identify which specific TDM measures are also offered as part of the C/CAG TDM Land Use Policy. 

Is there an expectation that cities provide evidence on why the applicant is using a specific measure?

No. C/CAG is expecting local jurisdictions to use their judgement. No further evidence required by C/CAG.

Will guidelines define how distance to high quality transit should be measured?

Page 3 of the Implementation Guide document defines distance to high-quality transit as the “traversable pathway” to and from the project site. On the contrary, this is not to be measured “as the crow flies”. The guidance document is available to view and download at

We are currently reviewing a 42-unit project partially affordable project that is located 100 feet from a Caltrain station. With a reduction applied should we submit for a review or an exemption?

That would depend on the projected ADT. The applicant and/or local agency staff needs to document the ADT, and if it is less than 100 the TDM Policy would not apply.

Regarding land use recycle. What is the threshold under a scheme where land is sitting vacant for period of time and it is considered greenfield now? The developer will say that it’s in their interest to use the previous use as abandoned land and will try to use that as baseline. Any guidance on that?

Typically, the local jurisdiction would have guidance in their zoning ordinance as to when a project is considered abandoned. The C/CAG TDM policy does not address this separately. 

(Due to interest expressed by attendees, it is anticipated that this definition will be more clearly addressed in a future near-term policy update)

Monitoring & Reporting

What is C/CAG’s formal role in the TDM-related development review process, and why is monitoring & reporting necessary?

C/CAG Will not formally “approve” applicant/developer-submitted documents. The intent of monitoring and reporting is to track countywide TDM implementation and performance. C/CAG envisions the utilization of the TDM Checklist as a method to demonstrate a qualifying project applicant will have the infrastructure and programs in place to successfully mitigate single occupant vehicle trips. As noted above, C/CAG encourages local municipalities to codify their commitment to compliance with the adopted Congestion Management Plan, including its Land Use Impact Analysis Program (TDM Policy).

Who will be responsible for monitoring and reporting ?

The monitoring and reporting process is a team effort that will be led by C/CAG, in partnership with will assist this task by facilitating standardized surveys on a biennial and triennial basis. Local staff assistance should only be required if the project sponsor is unresponsive in the required monitoring efforts or is not implementing the measures as required pursuant to the project approvals.

Does C/CAG intend to provide additional training, resources, or tools to make this initial calculation of ADT easier for inexperienced applicants?

It is anticipated that projects that trigger 100 ADT are of a size that would necessitate a Traffic Impact Analysis Report (TIA) and it is likely that the project sponsor would be familiar with the technical analysis to be pursued either in-house or through a contracted professional transportation planner/engineer/firm. Absent that, estimated daily trip generation for the proposed use may be based on the published ITE trip generation rates or other sources determined acceptable by the local municipality. For example, the C/CAG TDM Land Use Policy Update Implementation Guide contains text that refers to the U.S. Environmental Protection Agency Smart Growth Mixed-Use Trip Generation Tool (US EPA MXD) as an additional reference tool for determining trip generation. Appendix C of the C/CAG TDM Policy Update Approach contains references specific to ADT Trip Reduction Methodology.

Will the monitoring & reporting survey be provided online, for ease of use and distribution?

Yes, the survey document will be available soon.

What is the frequency of the monitoring & reporting process?

Table 4 in the Policy Approach document clarifies recommended reporting periods for different project types. 

It is re-emphasized that TDM implementation, monitoring and reporting is a collaborative effort between C/CAG,, the local municipality, and property manager/tenants.

What would be the process if it is determined a property owner that did not meet a good-faith effort to meet the [TDM] goals? Who determines what is a good faith effort?

The local jurisdiction shall determine whether the project has made a “good faith effort” to implement the TDM Checklist according to conditions of approval (COAs) placed on the project. In this context, “good faith effort” refers to demonstrable implementation progress as part of local municipal post-occupancy review (if applicable), as well as periodic post-occupancy surveying as part of this TDM Policy. 

The expectation is that Project sponsors/property owners will be held responsible for ensuring implementation of the TDM measures they have agreed to per the Checklist, which are enforceable through above-referenced COAs, including the associated monitoring and reporting process. Compliance shortcomings will be addressed in a collaborative manner. Issue resolution shall include C/CAG,, the local municipality, and the property manager/tenant, as necessary. 

Is there an intention to automate data sharing, entry and analysis to help minimize review and sharing across agencies? Planning uses Accela and Bluebeam to facilitate interagency review – would C/CAG and consider this approach?

Automating the review process to the highest degree possible is being considered for future application.

Self-certification seems light and may not be trusted, particularly for larger commercial development. What if cities want more stringent requirements, like actual driveway counts? Can they include those requirements in COAs?

Cities are free to require any additional measures in accordance with their own more stringent regulations and conditions of approvals and need to accept the associated monitoring responsibility.

How quickly can C/CAG staff review TDM plans? Cities are under legally mandated development review timelines, especially for housing. 

The TDM Land Use Policy Update has been simplified so that project applicants submit a TDM Checklist directly to the municipality with development review jurisdiction. C/CAG will not conduct development review as part of this process. Instead, it is incumbent upon the local municipality to notify C/CAG when they have received a TDM Checklist for projects with > 100 ADT. C/CAG, with assistance from, will then monitor progress towards project approval and subsequent TDM implementation at the project site. Meanwhile, it is the role of the municipality to review and approve the TDM Checklist as part of the municipality’s routine project application review.

How is tenant info obtained and shared with C/CAG or Will tenant info be collected up front? And by whom? Want to avoid administrative burden on city staff after occupancy.

There is a requirement in the checklist that there be a TDM coordinator for the program. That would be how we would get that information.

This is part of the ongoing challenge with implementation. The developer is the first point of contact, but ongoing TDM compliance generally shifts to the tenant. That is who would work with