A Sampling of Emissions Analysis Techniques for Transportation Control Measures

Introduction

Forecasting Approaches

Selecting a Method

Key Inputs and Outputs for Each Method

References

List of Acronyms

Overview - The Workbook of Transportation and Land Use Strategies for Reducing Mobile Source Emissions was prepared by the Regional Air Quality Council in Denver, CO in order to allow assessment of a wide range of local and regional strategies for improving air quality.

Strategies Addressed - Improved transit; HOV lanes; carpooling and vanpooling promotion; employer-based TDM; bicycle and pedestrian programs; telecommute and work hour strategies; pricing and subsidies; land use.

Methodology - Strategies are analyzed individually through a series of calculation steps. Trip and/or VMT impacts are based on elasticities or empirical evidence from the literature. Changes in emissions are calculated based on changes in VMT. The workbook can be used to analyze strategies applied at particular employment sites or for an entire area.

Data Requirements - Total employees, persons, or vehicles affected; information describing the strategy analyzed; various other parameters (i.e., baseline vehicle trips per employee, total regional VMT) depending upon the strategy. Default parameters are provided for average trip lengths, emission factors, etc., although the user can replace with their own parameters.

Outputs - Changes in VMT and emissions.

Level of Effort - The workbook is easy to use, but it is in paper format and calculations are not automated. Some effort may be required to gather baseline regional or local data.

Advantages - The workbook is a simple means of developing a rough estimate of the emissions impacts of a wide range of strategies. The elasticities and empirical data contained in the workbook represent the state of knowledge as of 1996. The workbook also contains a discussion of supporting strategies and policy design issues, as well as an assessment of the relative magnitude of impacts at a regional level.

Limitations - Elasticities and empirical factors derived from one situation may not necessarily be applicable to a specific local situation. Impacts calculated using elasticities are heavily influenced by the choice of baseline parameters (e.g., vehicle operating cost per mile).

Source/Availability - The Workbook of Transportation and Land Use Strategies for Reducing Mobile Source Emissions (April 1997) is available from the Regional Air Quality Council (303-629-5450, staff@raqc.org.)

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