Could bigger trucks spell lower productivity?

By James Aaron Cooke -- Logistics Management, 11/1/1999

Time is money, as the old saying goes. When highways are congested or shut down because of accidents, then shipments don't arrive on time and that costs shippers money in lost sales or delayed production runs.

That is why the Transportation Research Board needs to add "time" to the list of items it should examine as part of its Study of the Regulation of Weights, Lengths, and Widths of Commercial Motor Vehicles. The motor carrier industry is pushing for authorization to run even larger and heavier trucks on the nation's highways to increase shipping productivity. In response, Congress has asked the research board to analyze the impact of heavier, larger trucks on the economy, the environment, and safety.

Although most studies weigh the benefits of increased productivity against the potential safety hazards, I have a hypothesis that larger, heavier trucks actually pose a threat to the free flow of commerce and thus ironically, have a negative impact on the economy. This premise occurred to me this past summer when a truck accident along my commuting route--the Massachusetts Turnpike--closed the road completely for over an hour, forcing major vehicle diversion to secondary roads.

Although a highway shutdown is an unusual circumstance, traffic delays from truck accidents are not. It seems to me that whenever there's a major tieup that stalls traffic for more than 15 minutes, it's the result of an accident involving a tractor-trailer. If a 48-foot trailer or double trailer rig turns over on the highway, it often blocks more than one lane--unlike a collision between two cars, which obstructs but a single lane. In fact, I suspect that truck accidents--and not car accidents--block roads for the longest periods of time.

That's why I would suggest that the Transportation Research Board look into this area as part of its study. The board could gather truck-accident statistics for major metropolitan areas from traffic watch reports or police accident reports. It could then try to determine if there's any correlation between longer or heavier trucks and major traffic delays--those holding up highway traffic for more than 30 minutes.

At the risk of jumping to conclusions, I'd guess that such research would show that the trucks and trailer combinations currently allowed on the roads by federal law often have a serious negative impact on travel time. If this hypothesis proved true, then wouldn't it be reasonable to assume that the use of longer combination vehicles or heavier trucks would create even more time-consuming bottlenecks on the highway?

The point here is that highways are a vital resource to the economy and commerce. Traffic delays can impede shippers' efforts to create tighter supply chains because delivery appointments can't be met when the highways are clogged due to accidents. Hence, longer trucks, despite their promise of increased productivity for any single shipper, might actually reduce overall logistics productivity for all shippers.

When the Transportation Research Board looks at the issue of longer, heavier trucks this year, it can't just consider whether or not those vehicles will harm the environment. It can't just consider how many extra pounds they can or cannot haul. It can't just consider whether they'll pose more safety hazards on the roads. It also has to take into account the time factor. Because without free-flowing traffic and safe highways for efficient deliveries, increased freight-hauling capacity won't matter one bit.