Vehicle Miles Traveled (VMT)

Vehicle miles traveled (VMT) is a metric that identifies the amount and distance of automobile travel in one day. VMT is used by jurisdictions to determine the significance of transportation impacts in a manner that promotes the reduction of greenhouse gas emissions, the development of multimodal transportation networks, and a diversity of land uses. Half of California’s GHG emissions come from the transportation sector; therefore, reducing VMT is an effective climate strategy, which can also result in co-benefits such as increased public health.

To achieve the State’s long-term climate goals, California needs to reduce per capita VMT. This can occur under CEQA through VMT mitigation. However, VMT requirements can pose challenges to jurisdictions, especially those in more rural regions, because many opportunity housing sites are identified as high VMT.

Integration of VMT considerations and housing. One significant barrier to housing development is extensive environmental review. However, many land development projects including transit-oriented development, housing, retail, and office projects are presumed to have a less than significant impact and may not need to undertake CEQA transportation analysis if they are within one-half mile of a major transit stop or high-quality transit corridor or are 100 percent affordable housing projects. 

In more rural areas such as the San Joaquin Valley region, many potential housing sites would qualify as high VMT and do not meet the above exemption requirements. This poses a challenge to jurisdictions who are trying to remove barriers to housing development and meet the growing demand for housing. 

Many agencies use “screening thresholds” to quickly identify when a project should be expected to cause a less-than-significant impact without conducting a detailed study. Legislation allows jurisdictions to develop thresholds such as exempting affordable housing. Additionally, jurisdictions have the opportunity to encourage accessory dwelling unit and fourplex development through the small project screen. 

Integration of VMT considerations and safety. As jurisdictions are prompted to update their safety elements, the impact of sprawl-style development that is common in the San Joaquin Valley region on increased VMT may need to be addressed. Sprawl-style development has been shown to lead to elevated crash risk due to the higher VMT levels and design variables which influence speed and driver behaviors. This challenge presents jurisdictions with the opportunity to address transportation safety mitigation measures in their safety elements. If the safety element is updated concurrently with the housing element, this provides opportunity for jurisdictions to address concepts such as infill development with an integrated approach. 

Relevant State Law

Senate Bill No. 375 (SB 375) (2008) requires all Metropolitan Planning Organizations (MPOs) to update their Regional Transportation Plans (RTPs) and prepare RHNA allocations that result in development patterns and supporting transportation networks that reduce GHG emissions from cars and light trucks. 

Senate Bill No. 32 (SB 32) (2016) extends AB 32 by requiring the State to further reduce GHGs to 40 percent below 1990 levels by 2030 (the other provisions of AB 32 remain unchanged). The new law requires CARB to adopt the regulation so that the maximum technologically feasible emissions reductions are achieved in the most cost-effective way.

Senate Bill No. 743 (SB 743) (2013)  provides opportunities to streamline CEQA for qualifying urban infill development near major transit stops in metropolitan regions statewide. A transit-oriented infill project can be exempt from CEQA if consistent with a specific plan for which an EIR was prepared, and also consistent with the use, intensity, and policies of a Sustainable Community Strategy (SCS) or Alternative Planning Strategy that is certified by the California Air Resources Board as meeting its greenhouse gas reduction targets. Furthermore, under the bill, parking impacts are no longer considered significant impacts on the environment for select development projects within infill areas with nearby frequent transit service.


OPR, Technical Advisory on Evaluating Transportation Impacts in CEQA, provides advice and recommendations which agencies and other entities may use at their discretion. This advisory contains technical recommendations regarding assessment of VMT, thresholds of significance, and mitigation measures. 

OPR. General Plan Guidelines: Appendix B – SB 743 Safety Technical Advisory provides guidance on how to approach safety analysis given numerous potential risks, including VMT. 

Metropolitan Transportation Commission (MTC), Planning Innovations Webinars, identifies strategies to leverage State requirements for housing and VMT transportation analysis under CEQA (SB 743) to help meet your city’s RHNA numbers, Housing Element updates, and other climate and community goals. 


SB 10: Allows upzoning actions in “Urban Infill Sites” and “Transit Rich Areas”


“Urban Infill Site” is defined as a site that satisfies all the following:

  • A site that is a legal parcel or parcels located in a city if, and only if, the city boundaries include some portion of either an urbanized area or urban cluster, as designated by the United States Census Bureau, or, for unincorporated areas, a legal parcel, or parcels wholly within the boundaries of an urbanized area or urban cluster, as designated by the United States Census Bureau.
  • A site in which at least 75 percent of the perimeter of the site adjoins parcels that are developed with urban uses. For the purposes of this section, parcels that are only separated by a street or highway shall be considered adjoined.
  • A site that is zoned for residential use or residential mixed-use development or has a general plan designation that allows residential use or a mix of residential and nonresidential uses, with at least two-thirds of the square footage of the development designated for residential use.

“Transit Rich Areas” are defined as those within one-half mile of a Major Transit Stop which includes:

  • An existing rail or bus rapid transit station.
  • A ferry terminal served by either a bus or rail transit service.
  • The intersection of two or more major bus routes with a frequency of service interval of 15 minutes or less during the morning and afternoon peak commute periods.
  • Or a parcel along a “High-quality bus corridor” with fixed-route bus service that meets all the following criteria:
  • It has average service intervals of no more than 15 minutes during the three peak hours between 6 a.m. to 10 a.m., inclusive, and the three peak hours between 3 p.m. and 7 p.m., inclusive, on Monday through Friday.
  • It has average service intervals of no more than 20 minutes during the hours of 6 a.m. to 10 p.m., inclusive, Monday through Friday.
  • It has average intervals of no more than 30 minutes during the hours of 8 a.m. to 10 p.m., inclusive, on Saturday and Sunday.