Multimodal Transportation Impact Analysis for Site Development (MTIA)

ITE Adopts the MTIASD Recommended Practice

An Institute of Transportation Engineers’ (ITE) Technical Committee led by the ITE Transportation Planning Council has developed a Recommended Practice titled Multimodal Transportation Impact Analysis for Site Development (MTIASD). This Recommended Practice supersedes an edition of the similar title Transportation Impact Analyses for Site Development published in 2010 (RP-020D).

A transportation impact study is intended to predict the travel and parking demands of land use developments to allow developers and communities to address these demands in the most effective way. This publication summarizes the recommended practice for preparing and reviewing transportation impact analysis studies for new and expanding land developments. The MTIASD Recommended Practice encourages consistency in planning site access, on-site circulation, and off-site improvements for land developments. A secondary purpose is to foster a better understanding of the transportation-related aspects of development planning by those who participate in the process.

The state of transportation impact analyses has been evolving during the past several decades from being referred to as traffic impact analysis and having a primary objective of analyzing vehicles (e.g., automobiles, trucks) to an evaluation of safety, mobility, and access for all modes, hence shifting toward multimodal transportation impact analysis. Several factors have influenced this evolution, including nationwide environmental, safety, fiscal, and equity concerns, as well as the acknowledgement that not everyone owns an automobile or has a driver’s license. Furthermore, there is a realization that urban areas have finite space; even communities of lower densities can’t continue expanding road capacity indefinitely. Traveler behavior is influenced by system changes, so impact mitigation choices can be used to help achieve broader transportation system goals. Multimodal communities are more affordable, healthy, sustainable, resilient, and equitable, and this Recommended Practice will assist in the analysis and planning of multimodal networks.

This MTIASD Recommended Practice can be purchased on the ITE Bookstore.

What is the MTIA Project?

The update was designed to address areas as communities and practitioners seek guidance on how to evaluate the opportunities and constraints with innovative approaches to rethinking traditional TIASD approaches. The timing is therefore appropriate to transition from a traditional traffic impact analysis to a multimodal transportation impact analysis. The primary purposes of this Recommended Practice are to accomplish the following:

  • Identify steps necessary to make transportation impact analyses match an agency’s transportation policies, considering multimodal transportation and safety in addition to traditional techniques
  • Provide reliable guidance on short- and long-range planning of site design features (e.g., site access, circulation, and parking layouts) and off-site improvements necessary to provide a multimodal transportation system that satisfactorily accommodates mobility needs, including both onsite and off-site, considering the rational nexus between the site-generated demand and recommended transportation system changes
  • Assist developers and property owners in making critical land use site-planning decisions regarding traffic, transit, bicycle, pedestrian, and other modal needs and transportation aspects
  • Provide government review agencies with recommended practices useful in developing their own requirements and guidelines for achieving responsive and consistent review/approval of local multimodal transportation impact and access studies
  • Guide the transportation professional involved in conducting or reviewing transportation impact analyses by reflecting the state of the practice in all the potential steps of such a study

This Recommended Practice will help to achieve the following:

  • Clarify how to identify the contribution a particular site development makes to roadway system traffic loads (i.e., vehicular transportation impacts)
  • Provide a credible basis for estimating transportation improvement requirements for vehicular and non-vehicular modes attributable to a particular project
  • Assess compatibility with local transportation plans
  • Identify potential improvements to the transportation system or changes to a site development’s design to help address or mitigate anticipated impacts

Why Update the TIASD as the MTIA?

The purpose and need to update and replace the TIASD with MTIA is summarized in two formats from project kickoff activities in summer 2017:

During the 2018 ITE Annual Meeting and Exhibit, the project team hosted an idea wall to highlight some 50 proposed conceptual changes and get feedback. 


ITE would like to thank the following individuals for serving as primary authors of this publication:

  • Sarah Abel, SEED, RSP1, Toole Design (M)
  • Dan Hardy, P.E., PTP, Renaissance Planning (M)
  • Kevin Hooper, P.E., ITE (F)
  • Bradley Strader, AICP, PTP, MKSK (F)
  • Aaron Zimmerman, PTP, District of Columbia Department of Transportation (DDOT) (M)

The following authors assisted with the development of this publication:

  • Bill Brockenbrough, P.E., AICP, Delaware DOT (M)
  • Sarah Coakley, AICP, Delaware DOT
  • Chris Comeau, AICP-CTP, City of Bellingham, WA (M)
  • Michelle DeRobertis, Ph.D., P.E., Transportation Consultant (F)
  • Benjamin Palevsky, AICP, New York City Department of Planning (M)
  • Alan Sanderson P.E., City of Flagstaff, AZ (retired) (M)
  • Daniel Solomon, AICP, Gorove Slade (M)
  • Dan VanPelt, P.E., PTOE, Gorove Slade (M)
  • Brian T. Welch, AICP, Denver Regional Transportation District (F)

The following members served on the review panel for this publication:

  • William Capers III., PTP, The Maryland-National Capital Park and Planning Commission (M)
  • DJ Clark, P.E., PTOE, Sanderson Stewart (M)
  • John A. Davis, P.E., PTOE, F.ITE, City of Des Moines, IA (F)
  • Scott Davis, P.E., Washington State Department of Transportation (M)
  • Peter Koonce, P.E., City of Portland, OR (M)
  • Todd Litman, Victoria Transport Policy Institute (M)
  • Karyn A. Robles, AICP, City of Schaumburg, IL (M)
  • David Thatcher, Stantec (M)
  • Diane B. Zimmerman, P.E. (M)

Twitter Facebook LinkedIn YouTube Instagram