The Faster You Go, the More Expensive It Gets

Driving trucks at higher speeds make motor carriers more productive by getting the freight to its destination faster, the thinking goes.

But fleet managers have learned that speed costs money.

Productivity gains in getting a load delivered sooner are often offset by increased wear on tires and other components.

In 1995, 38 states used the federal maximum of 65 mph for highway speeds. Congress lifted the 65 mph ceiling in 1996 and permitted states to set their own speeds on certain stretches of highway. Now, 18 states have 65 mph limits, and 22 allow driving at 70 mph or greater.

In 1996, in anticipation of the speed limit increases, The Maintenance Council looked at truck components it thought would be affected by faster highway speeds. Now, follow-up studies three years later have shown that greater speeds can cost a fleet big dollars.

A study of tires on several truck fleets measured wear performance, resistance to irregular wear and casing durability. Using 55 mph as their base, researchers found that 80% of the fleets that increased their average speed reported a decrease in tire life.

Other findings in the tire report:

Higher speeds changed the footprint, with 67% of the fleets reporting greater irregular tire wear.

Faster speeds build up heat in the tire, causing the casing to break down sooner. Almost 80% of the fleets reported lower durability.

Tires’ contribution to rolling resistance decreases in relation to other factors, such as air resistance and energy losses from on-board equipment.

The bottom line? Though no dollar figure was put on the effects, 78% of the fleets that raised their average speeds reported increased tire expenses.

For the full story, see the April 5 print edition of Transport Topics. Subscribe today.