Serving clients in Arizona, California, Colorado, Hawaii, Iowa, Missouri, Nevada, New Jersey, New Maxico, Oregon, Tennessee, Texas, Utah, Washington .
(818) 697-6626
Services

Project Impact Determination of Development projects under CEQA Transportation Impact Analysis in Los Angeles County

Los Angeles County Traffic Impact Study Guidelines Section 3.1.4.2. - Project Impact Determination

  • Residential Projects: Daily vehicle trips, daily VMT, and daily residential VMT per capita for residential projects should be estimated using the SCAG RTP/SCS Travel Demand Forecast Model (as described in the Los Angeles County Senate Bill (SB) 743 Implementation and CEQA Updates Report). Transportation demand management strategies to be included as project design features should be considered in the estimation of a project’s daily vehicle trips and VMT (see Section 3.1.5 regarding TDM strategies),
  • Office Projects: Daily vehicle trips, daily VMT, and daily employment VMT per employee for office projects should be estimated using the SCAG RTP/SCS Travel Demand Forecast Model (as described Los Angeles County Senate Bill (SB) 743 Implementation and CEQA Updates Report7). Transportation demand management strategies to be included as project design features should be considered in the estimation of a project’s daily vehicle trips and VMT.
  • Regional Serving Retail Projects: The Scoping Document prepared by the project applicant and Los Angeles County Public Works will outline one of the following methods for impact determination:
  • Preparation of a market-study-based transportation analysis submitted by the project applicant that demonstrates the project area is underserved for the proposed retail use and that the project will shorten existing shopping trips by creating an intervening location between trip origins and current retail destinations.
  • Run the SCAG RTP/SCS Travel Demand Forecasting Model (as described in the Los Angeles County Senate Bill (SB) 743 Implementation and CEQA Updates Report7) with and without the project. Since the overall number of trips in the model is based on home-based trips and is balanced with home-trip productions, the total number of trips will not be influenced materially by the introduction of additional retail space. Rather, the model will redistribute home-shopping trips from other retail destinations to the proposed retail destination.
  • If the project is entirely retail, the following steps apply:
    • Determine the traffic analysis zone (TAZ) in which the project is located,
  • Convert the project retail land uses into the appropriate employment categories utilized in the model and adjust the socioeconomic parameters in the TAZ appropriately to reflect the removal of existing land uses and addition of the project,
  • Run the four-step model process for the model's existing base year for the four time periods in the model (AM peak period, midday period, PM peak period, nighttime period) for the base (“no project”) scenario and for the “plus project” scenario,
  • Calculate the total VMT on the model network for each time period and sum it to determine the daily VMT for each scenario. The total VMT should capture both employee and home-shopping trips. Subtract the daily VMT for the base scenario from the daily VMT for the “plus project” scenario to determine the net change in daily VMT.
  • If the proposed project is a mixed-use development including more than 50,000 square feet of retail, conduct steps similar to those described above. However, first create a “without retail” model scenario that includes the rest of the project’s proposed land uses and then create and run the four-step model for this “with retail” scenario. Subtract the daily VMT for the “without retail” scenario from the daily VMT for the “with retail” scenario to determine the net change in daily VMT.
  • Land Use Plans: Daily vehicle1 trips, daily VMT, and daily total VMT per service population6 for land use plans should be estimated using the SCAG RTP/SCS Travel Demand Forecast Model (as described Los Angeles County Senate Bill (SB) 743 Implementation and CEQA Updates Report7). Transportation demand management strategies to be included as project design features should be considered in the estimation of a project’s daily vehicle trips and VMT,
  • Unique Land Uses: Some projects will not fit into one of the above categories. In such cases, a customized approach may be required to estimate daily trips and VMT. The methodology and thresholds to be used in such cases should be developed in consultation with and approved by Los Angeles Public Works staff at the outset of the study,
  • Mixed-Use Projects: The project VMT impact should be considered significant if any (one or all) of the project land uses exceed the impact criteria for that particular land use, taking credit for internal capture. In such cases, mitigation options that reduce the VMT generated by any or all of the land uses could be considered.

 

Our Services are available throughout Los Angeles County including in 90019, 90020, 90021

 

Serving Both Public and Private Sector Clients

Based in Los Angeles California, our firm provides comprehensive transportation consulting services from conceptual planning onward, with the goal of delivering efficient, high-quality creative solutions and seeing them through to the completion of projects. We have skilled traffic engineers and transportation planners to undertake a variety of projects with confidence while meeting the needs of a diverse clientele.

Get a Quote