1

presented to presented by

Quick Reference Guide for Traffic Planner/Engineers for Generating Traffic and Activity Data for Project-Level AQ Analyses

NCHRP 25-25B Task 96

AASHTO Air Quality, Climate Change, and Environment Subcommittee

Helen Ginzburg, VHB, Inc.

Chris Porter, Cambridge Systematics, Inc.

March 6, 2020

Acknowledgments

Principal Investigator:» Helen Ginzburg (WSP, now VHB)

Key Staff:» Victor Teglasi (WSP)

» Pascal Volet (WSP, now Aimsun)

» Chris Porter (CS)

» David Kall (CS, now FHWA)

NCHRP Senior Program Officers:» Lori Sundstrom and Ann Hartell

Project Panel:» Christopher Voigt, Virginia DOT

(Chair)

» Charles Baber, Baltimore Metropolitan Council

» Brian Dunn, Oregon DOT

» Alan Horowitz, AJH Associates

» Subrat Mahapatra, Maryland SHA

» Marilee Mortenson, California DOT

» Timothy Sexton, Minnesota DOT

» Gabriel Contreras & Timothy Wood, Texas DOT

» Paul Heishman, FHWA Resource Center

Purpose

Assist traffic analysts who work with traffic data and models in providing the traffic data required for emissions modeling and air quality analysis for transportation projects

» Bridge the gap between the fields of traffic and air quality analyses

» Support early coordination to reduce delays

Supplement to NCHRP Report 765, Analytical Travel Forecasting Approaches for Project-Level Planning and Design

The Traffic – Air Quality Data Link

• Field Data Collection

• Project-Level Traffic Modeling

Traffic Activity Data

• Vehicle Emissions Models

• MOVES (EMFAC)

Emissions Quantities

• Air Quality Dispersion Models

• AERMOD

• CAL3QHC/R1

Pollutant Concentrations

• Calculate Design Values and Conduct Tests (NAAQS and BD/NB)

• Prepare Documentation

Summarize Results

Air Quality

Practitioners

Coordinate Early On:

Identification of potential traffic and air quality impacts

Availability of traffic data and forecasts

Study area/links included

Timeline for project development

Traffic data needs and requests

Plans for more refined traffic analysis

Sensitive locations/ receptors in project vicinity

Pollutants

Alternatives

Analysis years and time periods

Key assumptions

Guide Organized by Pollutant

Conformity NEPA

State

Environmental

Policies

Ch. 3 - Carbon monoxide (CO)

Ch. 4 - Particulate matter (PM)

Ch. 5 - Mobile source air toxics (MSAT)

Ch. 6 - Greenhouse gas (GHG)

Ch. 2 – Overview of Traffic Data Needs in AQ Analysis

Ch. 7 – Special Topics

Ch. 8 – References

Appendices

Ch. 2 – Traffic Data Needs Topics

Typical steps:

1. Preliminary assessment

2. Screening data/forecasts

3. Detailed data/forecasts

4. Mitigation

Traffic volumes

» Base year & forecasts

» Classification

» Temporal detail (hours)

» Generated & diverted traffic

» Background growth

Traffic speeds

» Existing and forecast

Other data

» Signal timing

» Start, parked, hoteling fractions

Pollutant-Specific Chapters

Data Sources and Methods Table

Project

Stage/Step

Traffic/ Activity

Input

Impact on

Emissions and

Concentrations Method Bas

e Y

ear

Fu

ture

Yea

r

References Comments

Project

Assessment,

Step 1

Intersection LOS

at locations

potentially

affected by the

project

Important if future

year LOS is D or

worse

LOS is usually an output of traffic

analysis or traffic simulation

software

X X NCHRP Report

765, 2.3.1, 2.4.3

If LOS is not included in the

general model output, NCHRP

Report 765 describes in detail

the HCM Sixth Edition

computational methodology

X X NCHRP Report

765, Section 10.4,

pp 252-257

Etc.

Ch. 7 – Special Situations

Advanced traffic modeling methods when using MOVES operating mode distribution or drive schedule inputs

Reevaluations under NEPA

Traffic mitigation measures as they are affected by the air quality modeling results

Litigation risk management

Ch. 8 - References

Traffic Data Sources

General Emissions and Air Quality Modeling Guidance

Guidance by Pollutant

Some State and Local Regulations and Guidance

Traffic Mitigation

Litigation Risk Management and Reevaluations

Appendices

A - Sample two-page “traffic information request forms” that list the key traffic data items required for CO, PM, and MSAT

B - Examples of traffic information provided for air quality analyses

C - Definitions for air quality modeling

D - Definition of “links” in air quality modeling vs. traffic analysis

Example Traffic Information Request Form

Further Information & Contacts

Guide published at:

» http://onlinepubs.trb.org/onlinepubs/nchrp/docs/NCHRP25-

25(96)_QRG.pdf

Ann Hartell, Senior Program Officer, ahartell@nas.edu

Helen Ginzburg, VHB, hginzburg@vhb.com

Chris Porter, Cambridge Systematics, cporter@camsys.com