Con-way Truckload, a nationwide full-truckload freight transportation company, announced this week it was making changes across its fleet of 2700 tractors to reduce the governed maximum speed from 70 miles per hour to 65.

By making the move, the carrier said it expects to save up to 2.8 million gallons of diesel fuel annually and reduce carbon emissions by approximately 62 million pounds per year.

Worthy aims, for sure, and one which, in theory at least, should result in slightly lower fuel surcharges to shippers.

But the move will also increase the travel time for Con-Way moves. Probably by just a small amount, given that the maximum speed decrease is about 7%, and trucks only move at maximum speed for some fraction of their total driving time.  Still, that means slightly longer travel times for shipments, which also can impact driver productivity (hours of service) and, ultimately, labor costs.

So, is that trade off worth it? Probably. But what about going to 60 MPG? Or back to the 55 MPH era of the 1970s?

Those are the questions that we are still far from answering in this Green era.