01029833

Component

https://doi.org/10.3141/1987-14

http://scholar.google.com...Zhai&publication_year=2006

Estimating the emissions consequences of surface transportation operations is a complex process. Decision makers need to quantify the air quality impacts of transportation improvements aimed at reducing congestion on the surface street network. This often requires the coupling of transportation and emissions models in ways that are sometimes incompatible. For example, most macroscopic transportation demand and land use models, such as TransCAD, TranPlan, and TRANUS, produce average link speed and link vehicle miles traveled (VMT) by vehicle and road class. These values are subsequently used to estimate link-based emissions by using standard emissions models such as the U.S. Environmental Protection Agency’s MOBILE6 model. In contrast, recent research with portable emissions monitoring systems indicates that emissions are not directly proportional to VMT but are episodic in nature, with high-emissions events coinciding with periods of high acceleration and speed. This research represents an attempt to bridge the gap in transportation and emissions models through the use of the real-world distributions of vehicle-specific power bins that are associated with average link speeds for various road classes. A successful effort in this direction would extend the use of transportation models to improve emissions estimation by using the limited output produced by such models. In addition, the variability of emissions and emissions rates over average speeds for a given facility type is explored, and recommendations are made to extend the methodology to additional facility types.

01042103

English

pp 128-137

2006

Transportation Research Record: Journal of the Transportation Research Board

0309099978

Print

Figures (8) ; References (13) ; Tables (2)

Air quality; Estimating; Exhaust gases; Land use models; Operating speed; Types of roads; Vehicle miles of travel

Emissions models; Light duty vehicles; Macroscopic models; Real world data; Speed profiles; Transportation models

Energy; Environment; Highways; I15: Environment

TRIS, TRB, ATRI

Mar 3 2006 10:35AM

• Air Quality Measurements Inside Diesel Truck Cabs During Long-Term Idling
• Cleaner Buses for Mexico City, Mexico: From Talk to Reality
• Comparison of Real-World Fuel Use and Emissions for Dump Trucks Fueled with B20 Biodiesel Versus Petroleum Diesel
• Development of the Traffic Air Quality Simulation Model
• Driver and Road Type Effects on Light-Duty Gas and Particulate Emissions
• Energy and Environmental Impacts of Roadway Grades
• Evaluation of Emissions from New and In-Use Transit Buses in Mexico City, Mexico
• Impact of Electronic Toll Collection and Electronic Screening on Heavy-Duty Vehicle Emissions
• Measuring and Modeling Emissions from Extremely Low-Emitting Vehicles
• Measuring Impacts of High-Occupancy-Vehicle Lane Operations on Light-Duty-Vehicle Emissions: Experimental Study with Instrumented Vehicles
• Methodology for Evaluating Mobile Source Air Toxic Emissions: Transportation Project Alternatives
• New Methodology for Development of Regional Vehicle-Mapping Tables for MOBILE Emissions Model
• Proposed Road Pollution Alert System Based on Lagrangian Wall Model
• Ultrafine Particle Number Concentrations from Hybrid Urban Transit Buses: Onboard Single-Diameter Scanning Mobility Particle Sizer Measurements
• Variability of Mobile Source Air Toxic Emissions Factors with MOBILE6.2
• Variability of Personal Exposure to Fine Particulates for Urban Commuters Inside Automobiles