Skip to content U.S. Department of Transportation/Federal Highway AdministrationU.S. Department of Transportation/Federal Highway Administration
Office of Planning, Environment, & Realty (HEP)

Status of TMIP Peer Reviews - Denver Regional Council of Governments (2004)

(PDF version)

PDF files can be viewed with the Acrobat® Reader®

Integrated Regional Model Vision Phase
Peer Review Panel Meeting #2:
Executive Summary
Meeting Date/Time: April 20, 2004, 8:30 AM - 4:30 PM
Meeting Location: DRCOG Offices, 4500 Cherry Creek Drive South


The content of this peer review report does not represent the opinions of FHWA nor does it constitute an endorsement, recommendation or specification by FHWA. The content of the report does not determine or advocate a policy decision/directive or make specific recommendations regarding future research initiatives. The report is based solely on discussions and comments during the peer review.

Table of Contents

I. Executive Summary

The following report summarizes the results of the second Integrated Regional Model (IRM) Vision Phase Peer Review Panel, funded in part by the Transportation Model Improvement Program (TMIP), which is sponsored by the Federal Highway Administration (FHWA). The one-day panel meeting was hosted jointly by the Denver Regional Council of Governments (DRCOG), the Regional Transportation District (RTD), and the Colorado Department of Transportation (CDOT) and was held at the DRCOG offices at 4500 Cherry Creek Drive South in Denver on April 20th, 2004. Participants included staff from the three above agencies, a panel of modeling experts from across North America, and consultants under contract to support the IRM project. The purpose of the meeting was to receive specific recommendations from the expert panel concerning model elements to be implemented in the up-coming IRM Update Phase.

This peer review session was the second of two to be held for the IRM Vision Phase. Its discussions were focused on technical details of recent advances in implemented travel and socio-economic forecasting models, and on the primary planning initiatives that regional policy makers have told the project team that they would like the modeling system to better support.

Jeff May, Erik Sabina, Simon Montagu, Jeff Romine, and Greg Erhardt of DRCOG facilitated the peer review meeting. Participants in the Peer Review Panel included transportation model experts from BMI-SG, KLK Consulting, the Portland METRO Planning Department, the University of Toronto, the North Central Texas Council of Governments, Environmental Defense, and the FHWA. Key consultants also participated from pbConsult.

II. Project Background

Near-Term Goals: The Integrated Regional Model Project

DRCOG, working cooperatively with CDOT and RTD (the principal transit provider for the Denver metropolitan area), is presently conducting the early phases of the Integrated Regional Model (IRM) Project. The IRM Project is a multi-stage effort, scheduled to be completed by 2005, whose purpose is to replace the existing land use and travel models in the region with a state-of-the-art, fully-integrated modeling system. The IRM Project was initiated following the completion in 2001 of the Travel Behavior Inventory Project, a comprehensive, 1.5 million dollar travel/activity/demographic survey of the metropolitan area, which provided the basic data necessary for the conduct of the IRM project.

The IRM project has been designed to take place in three phases:

Substantial project funding already is under contract. The project team is seeking additional funding, with the expectation that the total amount available will be adequate to develop a cutting-edge model, but will fall somewhat short of the total necessary to fund all improvements likely to be considered desirable by project participants.

Past Modeling: The Existing Denver Regional Model

Travel demand forecasting in the Denver area has been, for the past 15 years, conducted using a MinUTP-based model, with the following basic characteristics:

This model may be classified as "state of the practice" for major metropolitan areas during the late 1990s. However, it tends to be insensitive to many development and transportation market and policy initiatives currently being pursued in the region. To effectively support the planning of those initiatives, DRCOG feels that it must make significant improvements in the regional modeling system, employing the latest advances in modeling research and practice.

Present Modeling: The Refreshed Model

The product of the IRM Refresh Phase, now nearing completion, will be a significantly improved regional model, to be used while the next generation model is being developed. The refreshed model will include the following improvements:

In addition to providing more accurate results, this model should greatly enhance DRCOG's ability to support regional planning and policy analysis, as the data management and presentation capabilities of TransCAD are greatly superior to old DOS-based software such as MinUTP.

New Modeling: Expectations for the Updated Model

The project team's philosophy throughout the Vision Phase has been that all model elements and all possible improvement approaches are "on the table". The panels will help us to assess the feasibility of all desired improvements, to prioritize them, and to select those to be included in the project, given the inevitable funding constraints. It is not yet possible to say with certainty what elements will be included in the new model. However, the project team's current expectations include:

These and other possible improvements will be evaluated and decided upon during the Vision Phase.

III. Local IRM Panels: Technical and Policy Panel Recommendations

In addition to the institution of the Peer Review Panel, DRCOG, RTD, and CDOT also have convened two panels composed of transportation and planning professionals from the DRCOG region and adjacent regions. Both the Policy and Technical panels are composed of customers of DRCOG's planning and data analysis work. The panels include representatives of DRCOG member governments, regional transportation, planning, and environmental agencies, as well as representatives of environmental groups and private sector companies.

During the first round of panel meetings, in the fall of 2003, the local panels met first, so that the expert panel's discussions could be informed by the planning priorities developed by the local panels. In the second round of meetings, in the Spring of 2004, the expert panel met before the local panels, so that the expert panel's recommendations could be available for review and comment by the local panels. The local Technical Panel meeting was held on May 7th, 2004, and the local Policy Panel meeting on May 21st, 2004.

The primary purpose of the local panel meetings was to prioritize the top ten planning issues (identified by the local panels in the fall), to serve as a guide to the project team in prioritizing model improvements during Update Phase RFP writing and consultant contracting.

The top ten issues, in priority order, were:

  1. Effects of development patterns on travel behavior
  2. Sensitivity to price and behavioral changes
  3. Effects of transportation system and system condition
  4. Need for improved validity and reliability
  5. Ability to evaluate policy initiatives
  6. Better analysis of freight movement
  7. Ability to show environmental effects
  8. Modeling low-share alternatives
  9. Better ability to evaluate effects on specific sub-groups
  10. Reflect non-system policy changes (TDM, ITS)

IV. Peer Review Panel - Presentation Summaries

Approximately one half of the meeting was devoted to presentation of advanced modeling concepts and their effects by pbConsult and DRCOG staff. The other half of the meeting was devoted to peer review panelists reactions to these concepts, and to their formulation of recommended approaches.

Presentation: Overview and Ten Key Modeling Outcomes - Jeff May

Presentation: Technical background on advanced modeling techniques - Bill Davidson and Peter Vovsha, pbConsult

Overview of advanced modeling in current practice - Bill Davidson

Presentation of advanced modeling considerations - Peter Vovsha

Presentation of model design options - Peter Vovsha

Panel Comments

Presentation: Effects of proposed improvements on ten key outcomes - Erik Sabina

Panel Comments

Staging issues:

Feasibility of direct model transfer:

Operational and speed issues

Risk issues

Other issues:

Presentation: DRCOG Model Flow Chart - Greg Erhardt

Greg Erhardt presented DRCOG's vision of the IRM. This vision was developed as a flowchart of model steps, including both the land use and the travel models, and created independently for purposes of comparison with the consultant work.

Presentation: Data Integration - Simon Montagu

Simon Montagu discussed DRCOG's vision of a model data and programming structure.

Key points include:

Panel Comments

Socioeconomic Modeling - Jeff Romine

The current model is a home-grown version of DRAM-EMPAL. Key issues informing new model design are:

Goals for the modeling system include that it be:

Data access for users is critical!

Characteristics of UrbanSIM, the platform on which the new model will be built, include:

Policy Simulation - Jeff Romine

Jeff Romine presented DRCOG's approach to policy support modeling, growing out of the current Policy Options Model (2001) - a very simplified model. This model can't give "right" answer, but can give the direction and magnitude of effects. A little information is better than none. DRCOG wants to make it more user-friendly, and make it more comprehensive. It must provide information in real time! The next generation of policy models must:

Panel Comments

Other socio-economic modeling experience:

Model structure comments:

V. Panel Caucus Recommendations

Appendix A: Agenda

8:30 AM Welcome and Introduction Jeff May
8:45 AM List top ten model outcome priorities Jeff May
9:00 AM Present draft model structure options Jeff May
10:45 AM Structure options effects on ten outcomes Erik Sabina
11:15 AM Panel discussion of PB proposal  
12:00 PM Lunch  
12:30 PM DRCOG modeling concept approaches
Draft model flowchart
Data/Implementation Issues

Greg Erhardt
Jeff Romine
Simon Montagu
2:00 PM Panel discussion, questions  
3:00 PM Panel separate caucus session  
3:30 PM Panel presents recommendations  
4:00 PM Next steps, and thanks DRCOG

Appendix B: Attendees

Peer Review Panel Members:

Project Consultants:

Bill Davidson, Peter Vovsha, Joel Freedman, Rosella Picado - pbConsult

Project Team Members and Observers:

Erik Sabina, Jeff Romine, Jeff May, Amanda Penner, Simon Montagu, Matthew Barry, Shahida Mirza, Lan Nguyen, Christine Dumas - DRCOG; Brian Gardner - Federal Highway Administration; Lee Cryer - Regional Transportation District; William Johnson, Juan Robles - Colorado Department of Transportation; Mac Callision, Hui Liang Liu, City of Aurora; David Kurth - Parsons; Robert Yuhnke - Sierra Club.

Updated: 3/25/2014
HEP Home Planning Environment Real Estate
Federal Highway Administration | 1200 New Jersey Avenue, SE | Washington, DC 20590 | 202-366-4000