The Seaway

Transport and the Environment – Some Surprising Studies

Energy Efficiency Trends in Canada, 1990 to 2003 - Natural Resources Canada, 2005

• This is the tenth edition of an ongoing series of studies that track trends in energy efficiency, energy use and related greenhouse gas (GHG) emissions in Canada.
• The accompanying Energy Use Data Handbook provides data for 1990 to 2003 on cargo tonne-kilometers carried and GHG emissions by transport mode.
• The data show that GHG emissions per tonne-kilometre for trucking have fallen from 7.44 times as high as marine in 1990 to 7.09 times as high in 2003. Thus, while it is true that trucking has improved its GHG emission over this period, the marine mode is still far superior.

The Environmental Effects of Freight - OECD, 1997

This Organisation for Economic Co-operation and Development (OECD) publication provides emissions data for truck, rail and marine transport from several studies carried out in the early 1990’s in various OECD countries. These data were used to create ranges of emissions in grams per tonne-kilomtetre for Carbon Monoxide, Carbon Dioxide, Hydrocarbons, Nitrogen Oxides, Sulfur Dioxide, Particulates and Volatile Organic Compounds (VOC’s).

Table 1 (reproduced from the OECD paper)

Using these data, ratios of truck to marine and rail to marine were calculated at the midpoints of the ranges. These ratios show for each pollutant, how many times more (or less) emissions are produced by trucking and rail than by marine per tonne-kilometre of cargo carried and are shown in Table 2.

Table 2 (calculated from the OECD paper)

Thus these data indicate that depending on the pollutant in question, trucking produces between 8 and 16 times as much emissions per tonne-kilometer of cargo carried than marine.

Some clear conclusions can be drawn by comparing the data presented. Data on air pollution permit the most straightforward comparison. Despite substantial variation among the estimates within each transport mode, trucks are clearly much more polluting than trains or ships. This applies across all pollutants (CO, CO2, HC, NOX, SO2, particulates and VOC). The data suggest that rail may be more harmful than marine transport, however, this is much less clear. The use of different methodologies to derive the emission factors may well be more significant than any possible generalisation about the differences between marine and rail transport based on these data.

Environmental Impacts Of A Modal Shift - Minnesota Department of Transportation - Ports and Waterways Section

• the study looked at the impacts of shifting transportation of four commodities currently moved on Minnesota's river system and Great Lakes transportation to land transportation modes.
• The analysis determined that a shift to trucks from vessels would cause:
• An 826% increase in fuel use annually.
• A 709% increase in exhaust emissions annually.
• A 5,967% increase in probable accidents each year.
• The need to annually dispose of 2,746 used truck tires.
• An additional truck traffic load of 1,333 heavy vehicles each day in the study corridors.
• In the two corridors where rail is a possible transportation alternative the impacts of vessel to rail shift are:
• Fuel use increases by 331%.
• Emissions rise by 470%.
• Probable accidents grow by 290%.

A Comparative Study of the Environmental Impacts of Modes of Freight Transport in the St. Lawrence Axis (November 2000) - SODES

• The study was conducted by the consortium Hamelin-CFoRT-Gesco.
• Looked at environmental impacts of 4 scenarios in which cargoes would be shifted from land transport to marine and 5 scenarios where the reverse would occur.
• Environmental impacts assessed include fuel consumption, atmospheric emissions, noise, waste production, accidents and spills.
• The table below sums up findings from the study by showing how the different transport modes line up when energy consumption, emissions, accidents, spills and noise are compared. The index was formed by dividing the actual quantities obtained from the study by the value for the marine mode whose index number is thus 1.0 The indices indicate how many times larger the value is for other the modes. For example, rail consumes 2.2 times as much energy per tonne-kilometre as marine and trucking consumes 9.7 times as much as marine.

Modal Shift Study for the Great Lakes - St. Lawrence River Commercial Navigation -The Great Lakes Commission

• Purpose of study: to assess the comparative energy usage, emission impacts and safety risks of one transportation mode in relation to others.
• Results from this study show that vessel transport on the Great Lakes and St. Lawrence River is safer, uses less fuel and produces fewer emissions than either rail or truck when compared using equivalent commodity hauls.
• The study also addressed noise and congestion issues, and for these factors, the marine mode performed the best.