Traffic Analysis Toolbox Volume VI:
Definition, Interpretation, and Calculation of
Traffic Analysis Tools Measures of Effectiveness

1.0 Introduction

Traffic analysis tools play a critical role in prioritizing public investment in strategies employed by transportation professionals to relieve congestion. Traffic analysis tools help practitioners to:

Measure the operational performance of transportation facilities;
Evaluate various ITS strategies and innovative transportation management concepts;
Evaluate alternate designs and operational improvements;
Decrease the time and cost for evaluation and design of transportation facilities and systems; and
Reduce the risk and disruption to traffic caused by field experimentation.

1.1 Problem Statement

Use of the Highway Capacity Manual (HCM) and traffic simulation tools has become the standard approach for evaluating transportation design alternatives, operational performance, Intelligent Transportation Systems (ITS), and traffic operations strategies. However, the HCM procedures and traffic simulation tools seldom result in identical performance measurements. Moreover, there are no guidelines on interpreting these performance measurements. This leaves decision-makers and transportation professionals with the dilemma of identifying the true performance of the design alternatives and strategies.

1.2 Project Objectives

The goal of this study was to develop information and guidance on which MOEs should be produced, how they should be interpreted, and how they should be defined and calculated in traffic analysis tools. Specific objectives of the study were to:

Gain an understanding of the current use and interpretation, by transportation professionals, of some of the most commonly used MOEs generated by traffic simulation and analytical tools, such as HCM procedures;
Identify how field measurements are processed to estimate the MOEs used in conducting traffic analysis studies;
Provide guidance on how these MOEs are defined and calculated in the tools;
Develop an innovative approach to interpret these MOEs when conducting traffic analysis studies; and
Demonstrate the validity of the approach through a case study of representative tools.

1.3 Report Overview

This report presents innovative approaches for interpreting and presenting traffic simulation and analytical tool MOEs. This report considers alternative MOEs in addition to the Level of Service performance measure prescribed by the HCM. It recommends MOEs that decision-makers could use to interpret results from traffic analysis studies conducted by transportation professionals.

The Executive Summary provides more detail on the contents of this report.

1.4 Report Review Process

A draft of this report was submitted to the FHWA Contracting Officer Technical representative (COTR) and to a panel of volunteer experts in the application of traffic microsimulation to performance measurement for comment.

The volunteer experts were:

Invitee	Affiliation	Type
Scott Aitken	Quadstone	Vendor
John Albeck	Trafficware	Vendor
Jaume Barcelo	Aimsun	Academic/Vendor
Loren Bloomberg	CH2M-HILL	Private
Ken G. Courage	University of Florida	Academic
Mohammed Hadi	Florida International University	Academic
Steve Hague	California Department of Transportation	Government
David Hale	McTrans	Academic/Vendor
Michael Hunter	Georgia Tech University	Academic
Liang Hsia	Florida Department of Transportation	Government
Hani Mahmassani	University of Maryland	Academic/Vendor
Cathy McGhee	Virginia DOT Transportation Research Council	Academic
Arash Mirzaei	North Central Texas Council of Governments	Government
Kiel Ova	PTV-America	Vendor
John Shaw	Wisconsin Department of Transportation	Government

In addition, the report was submitted to the following project team members for review:

Team Member	Organization
John Halkias	Federal Highway Administration
James Colyar	Federal Highway Administration
Grant Zammit	Federal Highway Administration
John Tolle	Federal Highway Administration
James McCarthy	Federal Highway Administration
Vassili Alexiadis	Cambridge Systematics
Vijay Kovvali	Cambridge Systematics
Alexander Skabardonis	University of California, Berkeley

The efforts, advice, and suggestions of the volunteer technical reviewers, the Federal Highway Administration Project Team, and the Consultant Project Team are greatly appreciated. However, it should be noted that the opinions presented in this report are those of the author and not necessarily those of its reviewers. Remaining errors are the responsibility of the author.

1.5 Project Objectives Accomplished

Table 5. Accomplishment of Project Objectives

Objective	How Accomplished
Gain an understanding of the current use and interpretation, by transportation professionals, of some of the most commonly used MOEs generated by traffic simulation and analytical tools, such as HCM procedures.	Chapter 2 provides an overview of current practice. It describes MOEs used in practice and in research. It identifies commonly used tools for computing MOEs.
Identify how field measurements are processed to estimate the MOEs used in conducting traffic analysis studies.	Chapter 3 describes how MOEs are measured in the field.
Provide guidance on how these MOEs are defined and calculated in the tools.	Chapter 4 documents how MOEs are computed by a range of macroscopic and microscopic tools.
Develop an innovative approach to interpret these MOEs when conducting traffic analysis studies.	Chapter 5 presents a recommended approach to defining, calculating, and interpreting MOEs, which were reviewed by a panel of technical experts in Chapter 6, and refined accordingly. The final refined set of MOEs and their interpretation are provided.
Demonstrate the validity of the approach through a case study of representative tools.	Chapter 7 illustrates the application of the MOEs to two case studies taken from vehicle trajectory data developed under the NGSIM program. This chapter illustrates the computation and interpretation of the MOEs. The final set of recommended MOEs and their interpretation based on the results of technical review and the case studies are also provided.