NASHVILLE, Ind. -- A new study questions the oft-cited notion that shifting freight to rail through government incentives will actually result in a 'greener' transport system.

FTR Associates' Noël Perry, who authors a report titled Transportation Fundamentals, agrees that rail line haul is far more fuel efficient than truck per load, but maintains that this is just part of the energy equation and rail should face similar emission rules that the trucking does.

He suggests that reductions in greenhouse gas emissions can be achieved through improved access to intermodal terminals, equalization of rail and truck standards for production of potent NOx exhaust and modifying existing truck size and weight regulations to put more freight on the road per tractor-trailer unit.

"Existing market forces have already done an excellent job of maximizing fuel efficiency by allowing rail and truck to do what they do best," Perry says.

Rather, he concludes that for optimal energy efficiency one must look at the complete supply chain from start to finish, including the local pick-up and delivery function for which flexible trucks are far more efficient than rail. 

Trucks are getting proportionately greener
than rail at a more rapid pace.

When all factors are considered, most freight currently moving by truck would consume more energy if converted to a 100 percent rail move, he concludes.

Perry suggests that maximum energy efficiency might be gained from more transloading of freight between truck and rail, where truck is used for local transport and rail for the intercity movement.

"Government efforts should be directed at creation of more such truck/rail interchange terminals to make this option more accessible."

Modifying existing truck size and weight standards, which have been frozen for over 20 years in the U.S., would also improve transport's environmental footprint substantially.

Applying current truck emission standards to the railroads as well would also help reduce GHGs.

As Perry points out, one unit of NOx produces 310 times the global warming effect of one unit of CO2, the GHG normally tracked in carbon comparisons.

Upcoming EPA-mandated 2010 truck rules virtually eliminate NOx from modern engines.

Because of differences in the regulation of truck and rail diesel engines, rail locomotives currently emit an average of 4.5 times more NOx per horsepower-hour than truck. Further, when looking to the future, when both truck and rail NOx emission regulations will be tightened (truck next year and rail in 2015), new locomotives will still emit 6.5 times more NOx per horsepower hour than new trucks.