Overview

The Mitigation Fee Act, which begins with Government Code Section 66000, defines the necessary actions to establish, increase, or impose fees as a condition of approval of a development project by a local agency.  Recent legislation, including California Senate Bill (SB) 358 (2025), Assembly Bill (AB) 3177 (2024), and AB 2553 (2024) amended the code to specify that if the purpose of an imposed fee is to mitigate vehicular traffic impacts, then the fee rate shall reflect a lower rate of automobile trip generation associated with development in comparison with developments without certain characteristics, including: that it is within a transit priority area, the housing development is located within one-half mile of certain uses, and the project provides a limited number of parking spaces per residential unit. Further, a local agency (the County) shall not impose a land dedication requirement to widen the roadway if the requirement is for purpose of mitigating vehicular traffic impacts or achieving a vehicular level of service. The law provides for exceptions when the local agency makes written findings that are supported by substantial evidence in the record as part of the development approval process.  This overview is not intended as a complete statement of the legislation, which is available at the California Legislative Information site at SB 358, AB 2553, and AB 3177.
 

Eligibility Requirements

Chapter 2.53 Fees for New Development of the San Mateo County Municipal Code describes fees associated with new development impacts to existing County public roads and drainage systems. A housing project may be eligible for a reduced fee if it meets the requirements of Government Code Section 66005.1, including:   

  • Project must be within a transit priority area (Public Resources Code, Section 21099(a)(7)), which is a ½ mile radius (as the crow flies) of a major transit stop that is existing or planned. A major transit stop (Public Resources Code, Section 21064.3) is an existing rail or bus rapid transit station, a ferry terminal serviced by bus or rail service, or the intersection of two or more major bus routes with a frequency service internal of 20 minutes or less during the morning and afternoon peak commute periods. If the stop is planned, the stop must be scheduled to be completed before or within one year from the scheduled completion and occupancy of the housing development. See the “Resources” section below for potential tools.
  • Project is located within ½ mile from at least three of the following:
    • A supermarket or grocery store.
    • A public park.
    • A community center.
    • A pharmacy or drugstore.
    • A medical clinic or hospital.
    • A public library.
    • A school that maintains a kindergarten or any of grades 1 to 12, inclusive.
    • A licensed childcare facility.
    • A restaurant (means a retail food establishment that prepares, serves, and vends food directly to the consumer).
  • Project provides no more than one onsite parking space for zero- to two-bedroom units, and two onsite parking spaces for three or more bedroom units.

In addition, local agencies cannot impose a land dedication requirement on a housing development to widen a roadway if the land dedication requirement is for the purpose of mitigating vehicular traffic impacts, achieving a desired roadway width, or achieving a certain level of service, unless:

  • The housing project is not located within a transit priority area, and
  • The housing project has a linear street frontage of 500 feet or more.

Local agencies can impose a land dedication requirement as a condition of approval for traffic safety features if the agency makes a finding supported by substantial evidence that the requirement is necessary to preserve the health, safety, and welfare of the public. Further, it may require it to construct public improvements, including but not limited to sidewalk and sewer improvements.
 

Implementation

The Roadway Mitigation Fee is assessed during the Building Permit phase, prior to building permit issuance. Eligibility for reduced Roadway Mitigation Fees pursuant to this legislation will be assessed at the time of Building Permit submittal, and uses cited must be active at the time of submission. Legislation applies to housing development projects only, which is defined as a development project with common ownership and financing consisting of residential use or mixed use where not less than 50 percent of the floorspace is for residential use.

To support verification, applicants should provide a combined pdf of items under 1, 2, and 3 as part of Building Permit submittal:

  1. To confirm project is within a ½ mile of a transit priority area of an
    1. existing stop, please provide:
      1. map with transit stop location(s) and project location with a straight, direct line measurement in miles and feet from the nearest edge of the parcel containing the project site to the transit stop as pinpointed by a map sourcing data from 511.org (e.g., third party maps such as Google Maps) if it is within a public right-of-way, or to any point on the parcel(s) that make up the property upon which the stop is located. Map should include roadway network, parcel lines, APNs of project site, north arrow, scale, and legend.
      2. Transit operator(s) and route number(s) that serve the location(s).
      3. Hours of operation(s) and schedule during weekdays (6:00 – 9:00 a.m. and 3:00 to 7:00 p.m.) from the transit operators’ website with weblink to original documentation.
    2. planned stop, please provide:
      1. The Metropolitan Transportation Commission shares information with Caltrans to include in the California State GeoPortal, typically as part of the High Quality Transit Stops dataset, which must be filtered for planned stops. Please provide the stop location cross streets, including OBJECTID, and similar map as described above in A.a.i.
      2. Estimated timeline of project occupancy and evidence regarding the planned stop’s construction timeline.
  2. To confirm project is within ½ mile of at least three of the uses cited by the legislation, provide:
    1. Map with each use’s location and project location with a straight, direct line measurement in miles and feet from the nearest edge of the parcel containing the project site to the use, to any point on the parcel(s) that make up the property upon which the use is located. Map should include roadway network, parcel lines, APNs of project site, name of each use and category, north arrow, scale, and legend.  
    2. Google or other mapping service links to each cited use (e.g., relevant supermarket, park, community center, etc.).
      1. If use cited is a childcare facility, provide printout from California Department of Social Services cite (Social Services - Community Care Facility search) that demonstrates licensed status and is aligned with facility location and/or evidence of licensee associated with location.
  3. To confirm project meets parking maximums, provide:
    1. Table of building square footage by use type
    2. Table with unit type, number of units, parking spaces provided per unit, and total number of parking spaces for residential uses
    3. Total number of parking spaces for project overall
    4. Describe how parking spaces will be allocated (example – assigned parking space by unit, shared parking garage for all tenants – including commercial uses, etc.)
       

Resources

Web mapping tools such as the Caltrans High Quality Transit Stops Online Map, with filter applied on “hqta_type” for major bus, ferry, rail or brt, can help identify potential stops and qualifying parcels. Most transit service in San Mateo County is provided by SamTrans, Caltrain, and BART. 

San Mateo County Municipal Code, Chapter 2.53 Fees for New Development includes the current fee schedule.

The Planning and Building Fee page includes the most current fee schedule.
 

Contact

Chanda Singh, Senior Transportation Planner