What does it mean to say you run a “green” fleet? Is it just a matter of buying the latest trucks with hyper-compliant engines? Of spec’ing the latest in aerodynamics? It’s both, of course – and much more besides.

Put another way, going green is not just a matter of tailpipe emissions, according to Kary Schaefer, general manager of marketing and strategy at Daimler Trucks North America. It’s also about efficiency and uptime, and everything stands on three pillars: safety, connectivity, and propulsion systems. The truly green fleet is one that wastes as little as possible, in every sense.

The keynote speaker at the recent Green Truck Summit in Indianapolis, Indiana, ahead of the Work Truck Show, Schaefer cited a major fleet that used to see one in every four of its trucks involved in an accident each year. After installing advanced safety systems such as stability control and collision mitigation, that ratio became one in 19. Rear-end collisions dropped dramatically. Such gains in uptime, in productivity, make a very good business case for safety, Schaefer said.

Connectivity is a means to an end, she continued, one key result being mounds of data that offer “significant opportunities” in many operational areas. And it’s not a technology restricted to highway trucks, she added. Connectivity is just as useful in the vocational world, for example in driver coaching.

The buzz around electric trucks suggests they’re being seen as the ultimate in “green” trucking, but don’t hold your breath. There are hurdles to leap, Schaefer said, in moving the idea forward: range, weight, cost, and charging.

Battery costs have been diminishing, she said, but could well go up as demand increases. The high cost of replacing a battery pack is another issue, and we’re a long way from figuring out residual values for electric trucks.

Another key matter is the price of electricity, which changes almost daily and ranges widely from region to region. Typical costs go from five cents per kilowatt hour all the way up to 13 or 14 cents, she said.

And of course there’s no meaningful charging infrastructure at the moment, which presents a big question mark as to when and where.

Diesel remains king in terms of efficiency, she concluded, because of its high energy density that isn’t matched by any other fuel, electricity included. Natural gas has a place, too, where noise abatement is an issue or where near-zero emissions are mandated, but “diesel is here to stay for a long, long time.”

What we can do right now to go “greener,” she said, is renew the fleet to modern emissions standards. There remain too many older trucks on the roads adhering to pre-EPA2010 rules.

To which I’ll add an observation: On the 1,100-mile round trip that took me to Indianapolis, most of it on I-69, I passed hundreds of ordinary tractor-and-van-trailer units. Just four of them had trailer boat tail devices of one description or another, three of them deployed, one of them broken. And at best, only about 15% of the van trailers I saw had skirts. These are simple, effective aero tools that save fuel and money with short payback times, but we don’t seem to be spec’ing them.

My “study” was anything but scientific, but I was left with the impression that we’re not taking this green thing very seriously.