SBCTA is leading an SB 743 Implementation Study to refine the methodology outlined here and develop tools for VMT screening. Analysts and the County should monitor these efforts and update this guidance as new information and tools become available.
Projects that serve the local community and have the potential to reduce VMT are exempt from completing a VMT assessment. These projects include:
- K-12 schools
- Local-serving retail less than 50,000 sq. ft.
- Local parks
- Day care centers
- Local-serving gas stations
- Local-serving banks
- Student housing projects
- Local-serving community colleges consistent with RTP/SCS assumptions
- Projects generating fewer than 110 daily vehicle trips (e.g., 11 single-family housing units, 16 multi-family units, 10,000 sq. ft. of office space, 15,000 sq. ft. of light industrial space, 63,000 sq. ft. of warehousing, 79,000 sq. ft. of high cube transload and short-term storage warehouse, or 12 hotel rooms)
- Projects within a Transit Priority Area (TPA) as determined by the most recent SCAG RTP/SCS
- Projects within a low VMT generating area
For other projects, VMT should be estimated by multiplying average trip length by trip generation for the project. Average trip length information should be obtained from the SBTAM model, which also provides trip generation rates. Using SBTAM for both metrics ensures consistency when comparing project VMT per person/employee to the regional VMT per person/employee.
According to OPR guidelines, specific VMT components for assessment include:
- Residential Projects: VMT/Person for all home-based trips
- Employment Projects: VMT/Employee for home-based work trips, applicable to office, industrial, governmental, and institutional projects
- Regional Retail: VMT/(Employee + Visitors) for non-home based, home-based work, and home-based other trips
- University (with on-campus housing): VMT/(Person + Employee + Student) for home-based work, home-based other, and non-home-based trips
- Mixed-Use Projects: Analysis consists of home-based work, home-based other, and non-home-based trips
The impact criteria require comparing the project VMT per person/employee to that of the unincorporated County, derived from SBTAM for comparison. This should align with the project's environmental baseline, typically the notice of preparation or the initiation of technical studies. Linear interpolation between the base year and future year model projection horizons should be used to estimate VMT per person/employee for the region.
A cumulative VMT analysis should also be performed. This involves comparing the unincorporated VMT per person/employee with the project to that of the RTP/SCS projections. If the project is consistent with the RTP/SCS, no cumulative assessment is needed. Otherwise, the user has two options:
- Add the proposed land uses to the travel demand model, complete a full model run, and compare VMT per person/employee to RTP/SCS assumptions.
- Hold regional land use control totals constant and determine where development would not occur if the proposed project happens. This may involve an economist, a land use allocation tool, or reviewing future growth within a 5-10 mile radius of the project and proportionately decreasing development in those TAZs.
For projects likely to increase congestion along major corridors, a network-based VMT assessment should be completed for the cumulative year (with and without the project). Countywide network VMT should be evaluated to determine if project-induced congestion displaces regional through trips, increasing VMT relative to the RTP/SCS. Total VMT can be used if future land use is consistent between scenarios, or VMT per person/employee if not.
Our Services are available throughout San Bernardino including San Bernardino city with Zipcodes 92411, 92412, 92413, 92414, 92415