Can Switching Heavy Duty Trucks to Rail Transport Reduce Carbon Emissions?
President Obama included the recent 2014-18 heavy duty vehicle (HDV) fuel economy standards as part of his announced ‘Climate Action Plan’. The new fuel standards were developed in 2011 to improve the efficiency of future HDV’s, which includes 18-wheel tractor-trailers used to transport a large percentage of freight intercity within the U.S. While possibly increasing the fuel efficiency of heavy duty 18-wheelers can significantly reduce future U.S. carbon emissions, the Climate Action Plan fails to consider other potentially more effective alternatives such as replacing current HDV freight transport with more efficient Railroad transport. Should the Administration have included replacing HDV Trucks with Rail transport in the new climate policy?
Why Include the New HDV Fuel Standards in the Climate Action Plan? – The Transportation Sector is the largest consumer of petroleum fossil fuels and the second largest source of carbon emissions within the U.S. Different modes of transportation consume different volumes of petroleum motor fuels. Refer to the following bar-chart.
Data Source: EIA AEO 2013 for CY2012.
The above chart clearly illustrates why the original light duty vehicle (LDV) fuel economy (CAFE) standards were first created in the mid 1970’s. The petroleum fuels consumption of LDV’s are the largest within the Transportation Sector and increased fuel efficiency standards would have the greatest impact on reducing future U.S. petroleum consumption. Since the heavy duty/medium duty vehicles (HDV/MDV) are the second largest consumers of petroleum, the Administration recently developed new fuel economy standards to reduce the petroleum consumption of this transportation mode; CY’s 2014-18.
Each transportation mode consumes different types of petroleum motor fuels, which have different carbon intensities or emissions per unit volume consumed. Based on EIA carbon coefficient data the total annual carbon emissions for each transportation mode were developed. Refer to the following bar-chart.
Data Source: EIA AEO 2013 for CY2012. Petroleum consumption data converted to annual carbon emissions based on EIA emission coefficient data.
Due to the relatively large volumes of motor fuels consumed by the LDV and HDV/MDV Freight fleets, these transportation modes contributed to the largest fractions of the total Transportation Sector’s carbon emissions; followed by the Passenger & Freight Aircraft mode. The LDV, HDV/MDV and Aircraft transportation modes contributed to 58%, 18% and 9% respectively (or 85%) of total Transportation Sector 2012 carbon emissions. Other transportation modes carbon emission contributions are relatively small and vary from 2.8% (International Marine Shipping) down to 0.2% (Passenger Railroad).
Effectiveness of the New HDV/MDV Fuel Standards – The U.S. economy currently transports about 4.3 trillion ton-miles of goods-freight annually between cities and ports. On average 31% is transported by HDV/MDV Trucks and 39% is transported by Rail. The balance is transported by Marine, Pipeline and Air. The majority (>80%) of HDV/MDV freight transport are heavy duty, up to 18-wheeler tractor-trailer rigs; powered by diesel engines. Diesel engines are used due to the high horsepower-torque required to haul heavy loads (up to 80,000 lbs. GVWR) and the relatively high fuel efficiency compared to alternative ICE’s.
One of the largest operating expenses for Commercial and Private Freight transport owners is normally fuel costs. For this reason they are highly motivated to purchase the highest fuel efficiency HDV’s and make upgrades to existing HDV’s such as improved aerodynamics and lighter weight fabrication materials. Despite these normal market incentives to purchase-operate the highest efficiency HDV’s, the EPA and NHTSA developed new fuel efficiency standards that covered HDV’s for the first time in 2011. The EPA’s regulatory priority was to reduce HDV tailpipe emissions 2014-18 including greenhouse gases (GHG) and the NHTSA’s apparent priority was similar to past LDV CAFE standards.
During the rules making process the NHTSA and EPA determined that new HDV/MDV fuel efficiency standards would cumulatively save up to 530 million barrels of petroleum oil during 2014-18 and reduce GHG emissions by 270 million metric tons (MMT), carbon equivalent. These fuel efficiency standard savings would be equivalent to reducing petroleum motor fuels by 290 thousand barrels per day (KBD) and associate carbon emissions by 54 MMT/yr. The fuel and GHG or carbon (equivalent) emission reductions from the recently proposed 2014-18 standards are, however, theoretical and likely inflated. Based on historic CAFE standards performance, more accurate fuel savings should be expected to be about 80% of published levels. (Refer to the ‘U.S. CAFE and EPA Adjusted Vehicle Fuel Mileage – 1975-2009’ graph in a recent post on this subject). Average fuel & carbon emission reductions should more accurately be about 230 KBD & 43 MMT/yr. 2014-18. This represents a reduction in AEO 2013 projected (MD/HD) ‘Freight Trucks’ average fuel consumption and associated carbons emissions of 8% and 11% respectively for 2014-18.
Alternatives to HDV Intercity Freight Hauling and Reduced Fuel Consumption – Historically the U.S. relied primarily on the Railroads for transporting most freight cross country and between major cities. Prior to the 1950’s, the Railroads dominated both freight and passenger transportation. In the mid 1950’s the combination of the Federal Government creating a new interstate roads systems, growth in intrastate roads, and the rapid development of HDV Trucks and diesel engine technologies led to significantly displacing Railroad freight transport utilization over the years. Unlike Trains that were limited to transporting freight to locations along existing rail-lines, HDV Trucks could access most any location along the growing inter-/intrastate roadway systems. In addition, HDV’s had much more flexibility to schedule freight pickups and deliveries than Trains that generally operated around fixed and inflexible schedules. And, as the Railroad track infrastructure declined over the years, the flexibility to move freight around the country by rail also declined.
Despite somewhat more limited rail-line infrastructure, Trains have one huge advantage over HDV Trucks; fuel efficiency. Today a state-of-art high efficiency HDV Truck averages about 5.8 miles per gallon. This is equivalent to 1190 Btu/ton-mile petroleum diesel consumption (40,000 lb. average GVWR basis). Typical freight Trains average about 290 Btu/ton-mile petroleum consumption, which makes Railroad transport over 4-times more fuel efficient that HDV Trucks.
Possible Benefits of Displacing HDV Trucks with Rail Freight Transport – If State and Federal Governments were to strongly support expanding the use of Rail Transport for moving intercity freight, the U.S. could possible reduce HDV Truck fuel consumption and associated carbon emissions by levels much greater than the latest EPA/NHTSA HDV fuel efficiency standards. By replacing up to 25% of current HDV Truck freight transport with Rail transport total U.S. intercity freight transport mix would become 24% truck and 46% rail. This would effectively reduce average 2014-18 HDV petroleum diesel consumption by an additional 490 KBD (over the EPA/NHTSA new HDV fuel standards) and associated carbon emissions by an additional 68 MMT/yr.
Reducing U.S. total carbon emissions by 68 MMT/yr. is equivalent to effectively doubling the current total U.S. renewable wind + solar power generation capacity (based on displacing an equivalent amount of natural gas peaking/intermediate power generation capacity fossil fuel consumption). Reducing U.S. total petroleum consumption by an additional 490 KBD would also triple the benefits of the new HDV fuel standards, which would substantially reduce the need for oil imports and increase future U.S. energy security.
Pros and Cons of Displacing HDV Trucks with Rail Freight Transport – Clearly the largest advantage HDV Trucks have over Rail is scheduling and shipment pickup-delivery flexibility. However, with strong support from States and Federal Agencies existing rail-line systems could be expanded to increase the current number of cities and towns accessible by Rail. One of the primary reasons why the above analysis only assumes replacing 25% of HDV Truck freight with Rail is the fact that accessing all small towns will not be cost effective or practical. A significant percentage of HDV/MDV Trucks will still be required to off-load rail shipments in more numerous, but still generally centralized locations, and transport-distribute the freight to the final delivery points. Another factor affecting flexibility will be the timing-scheduling of shipments. ‘Just-in-time’ supply chains have made large advancements in materials/goods supply-logistics management over the years. These include improved inventory management controls, shipments location-status tracking systems, demand forecasting, and many other innovations. These state-of-art management systems must be updated and adjusted for the additional-numerous constraints found within current and possible future Rail transport systems. In some cases optimizing supply chains may mean adjusting inventories as needed for possibly somewhat slower overall goods transport times of predominately Rail based systems.
Other improvements to better optimize Rail based transport supply chains may mean changing logistics and operational expectations within many markets. Services such as overnight or next-day shipping-delivery probably need to be reviewed-limited as far as fuels consumption impacts. It may be necessary to slow down delivery time expectations of consumers for non-emergency goods in order to minimize U.S. fuel consumption and carbon emissions per ton-mile. Other constraints such as existing RR Union contracts that may sub-optimize overall transport system scheduling-timing and fuel efficiency could also require modifications to eliminated unnecessary delays. Another major political-economic factor that will also arise will be the obvious impacts on the Trucking Industry. Significant freight transport market-share loss and associated income impacts will be strongly debated as support for more efficient and lower carbon Rail possibly gains momentum.
Switching HDV Trucking to Rail also presents many additional potential advantages and future benefits. Besides reducing the HDV wear-and-tear and associated costs for maintaining nearly all highways and roadways, increasing the infrastructure, terminals and numbers-usage of Trains potentially creates many other clean energy opportunities. In nearly all cases the bulk or intermodal freight shipments must be transferred and distributed to their final destinations via. MDV/HDV Truck transports. These more centralized on-road supply chain distribution systems provide the opportunity to utilize increased alternative fueled vehicles such as natural gas ICE MDV/HDV Trucks. Natural gas motor fuels are more ideally suited for shorter-range transport that utilizes centralized (commercial) re-fueling stations. Since displacing diesel motor fuels with natural gas generates less than 30% of the carbon emissions, the added carbon emission benefits could be quite significant.
Another potential advantage of expanding the rail-line infrastructure within the U.S. is possibly further expanding Passenger Rail. The added railways needed for displacing HDV transport with Rail should provide a potential synergy to expand Passenger Rail within and across state-lines. One final advantage of substantially expanding Railroads will be the possible future synergy with electrification of this transportation mode. Electrifying generally more centralized transportation modes should be more cost effective than developing extremely more numerous and dispersed individual, lighter duty electric vehicles.
In Conclusion – Switching 25% of HDV freight transport to Rail will provide substantial benefits to reduced U.S. carbon emissions and increased U.S. energy security. If the current Administration truly supports minimizing U.S. carbon emissions, they should be advocating restoration and expansion of Railroad Freight transport across the country in the very near future.
Energy Consultant and Professional Engineer. 35 years experience in petroleum & clean energy businesses. Education: Chemical Engineering/Chemistry degrees from U.C. Davis and MBA from Saint Mary's College/U.C. Berkeley. Lifetime student of the natural sciences. Experienced in refining design/operations/maintenance, economics & project development/management, business development, energy ...
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