Developing Accurate Ports Emissions Inventories

Focus Area

Air Quality


Air Quality







Research Idea Scope

TERI Administrator Note (Feb 2009) – International Association of Ports and Harbors – TOOL BOX FOR PORT CLEAN AIR PROGRAMS; HOW TO CONDUCT AN EMISSIONS INVENTORY, December 2007

Research Objectives:

The objectives of this research are to develop 1.) a systematic methodology for analyzing land- and water-based traffic at ports and 2.) a tool for estimating emissions from this activity. It is proposed that traffic and activity at a Great Lakes port be the focus of this research given these ports’ importance in the nation’s freight network, unique characteristics, and manageable size. The results of this research, however, will be applicable beyond Great Lakes ports.
Background and Significance:
            The United States’ strong dependence on imports continues to increase demand on the nation’s waterways, rail lines, and highways. It is estimated that within the next 20 years, international and domestic marine cargo will double.1 Ports, where a great deal of intermodal activity occurs, are a key link in the transport of goods across the country. The confluence of waterborne vessels, trains, and heavy-duty trucks at ports, however, is creating congestion and air quality problems that seem likely only to increase.
            Despite this impact on the nation’s transportation infrastructure, metropolitan planning organizations treat ports relatively simply within urban travel modeling frameworks.   In these frameworks, ports are identified as “special attractors.” A certain number of trip attractions is assigned to the port but typically no satisfactory analysis of the spatial and temporal patterns of trip attractions is completed. More accurate methods to analyze and forecast port-related traffic would help state DOTs generate more accurate predictions of traffic characteristics and traffic levels on urban roadways near ports.
            Coastal ports such as the Port of Los Angeles and the Port of Long Beach have received some measure of detailed study. The Great Lakes ports, however, are a drastically understudied yet unique and critical element of the nation’s freight movement system. For example, one-third of freight transported through the United States has its origin or destination in the Great Lakes region.2 However, it is estimated that the freight moving across the upper Midwest (MN, WI, IL, IN, MI, OH) will increase by 50% by 2020.3 This increase will further stress all modes of freight transport in the region, which are already congested.3 A strong need for more information about freight transfer in this region, including that occurring at ports, exists for several reasons.   First, these data will improve MPOs’ forecasting of port-related traffic as noted above and in the research objective. Second, many Great Lakes ports (e.g., Port of Chicago, Port of Cleveland) are in non-attainment areas for ozone and particulate matter. A better understanding of the role that vehicles and vessels involved in freight transport play in air quality problems in these areas will lead to improved emissions inventories for the SIP and conformity processes. This knowledge will also inform action to reduce congestion and air quality impacts at ports. One metropolitan planning organization, the Northeast Ohio Areawide Coordinating Agency, has started to consider ways to reduce emissions at their local port – the Port of Cleveland. The port has responded by beginning to inventory vessel and rail traffic at the port.4
Developing a methodology for creating an inventory for vessel, locomotive, and truck trips to a Great Lake port would address a significant knowledge gap in regional transportation planning. The results of the research, however, would be applicable nationwide. If this proposal is selected, the consulting team selected for the project will gain the support of a binational agency that works with Great Lakes ports to help formulate the project and serve as a liaison with a Great Lakes port. Additionally, two faculty members at a Midwest university, experts in transportation systems, have pledged technical support.
Specific Tasks and Time Required:
This project, which can be divided into three stages, will take twelve months.
Stage 1: Background Study – Two Months
·         Complete literature review of methods to estimate ports-related emissions and traffic. Emission factors for the type of waterborne vessels known as “Lakers” will require special attention because they use a category 2 rather than category 3 engine.
Stage 2: Data Collection – Four Months (two summer, two winter)
·         Generate an inventory of trucks, locomotives, rail cars, waterborne vessels, and cargo handling equipment operating at the port. Note that this task would require more time at a large coastal port.
·         For each kind of type of waterborne vessel (Laker, Domestic Saltie, International Saltie) arrival at the port, determine the activity level of the vehicles and equipment involved in loading and unloading freight
·         For each type of freight (e.g., coal, iron ore, grain, etc.) and waterborne vessel, determine how many train cars are needed to transport the shipment away from the port.
Stage 3: Data Processing, Product Development, and Reporting – Six Months
·         From traffic and activity data, estimate
o       the average number of truck trips to and from the port
o       the average number of rail cars and locomotives that travel in and out of the port
o       the total emissions associated with the activity involved in vessel and railcar loading and unloading
·         Develop a spreadsheet or other tool to calculate annual port emissions and truck, railcar, and locomotive trips. The tool should also estimate emissions from cargo handling and other port equipment.
·         Report annual emissions from the selected port for 2005.
TERI Administrator Note (June 2007): Related Research
TxDOT; Develop Emissions, Truck Trips and Railcars Estimation Methodology for Major Texas Ports (Research Underway)

As with the growing domestic and foreign trade, port-related traffic and activities have been steadily increasing and this trend will continue in the future. An inventory of port emissions is a crucial step for a region to comply with the State Implementation Plan (SIP) required by the Clean Air Act (CAA). Port related emissions mainly come from mobile sources categorized as sea-side marine vessels and land-side trains and trucks. The Texas Department of Transportation (TxDOT) is interested in a systematic analysis and forecast of spatial and temporal patterns of port related traffic to improve the estimations of traffic characteristics and emission levels on roadways around ports in nonattainment areas. This project will review existing methods in literature and select appropriate procedures to estimate various sources of port emissions. The emissions from marine vessels can be examined by following EPA’s emission inventory guideline and that of non-road port engines and equipments can be computed using EPA’s NONROAD model. This study will emphasize the analysis of port-related traffic and their associated mobile source emissions. A complementary approach of commodity-based and vehicle-based methods will be employed to measure the truck and rail traffic flows from and to ports. The number of trucks and railcars in and out of the port is associated with vessel loading and unloading. The vehicle miles traveled (VMT) of port-related truck traffic together with idling, age, and other truck characteristics will be utilized to estimate the emissions from port-related trucks. Railcar emissions are developed from fuel consumptions for linehaul locomotives and switch yard locomotives. A spreadsheet-based package will be developed to calculate port-related truck trips, rail cars, and emissions. The models in the package will be validated and evaluated in an empirical study on the Port of Houston. They will be
further implemented and tested in a case study on the Port of Beaumont.

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