An assessment of the safety and efficiency of log trucks with increased weight limits on interstate highways in Wisconsin and Minnesota, USA

ABSTRACT

Design standards for the Federal Interstate Highway System in the US are generally higher than those on other roads within most states, making it the safest road system in the US. Federal law prevents states from enforcing vehicle weight limits on interstate highways that deviate from established Federal weight limits or state-specific grandfathered weight limits or exceptions. As a result, trucks hauling logs at state-legal limits must travel on other roads, passing through towns/cities and school zones where they may encounter on-coming traffic and intersections. All these encounters increase the risk of an accident. This study compared fatality rates of log trucks to other heavy trucks in the lower 48 states, road damage cost estimates for interstate and non-interstate roads and assessed the impact of relaxing interstate weight limits on various factors for hauling logs along three travel corridors in Wisconsin and Minnesota, USA. On a per-load basis, log trucks have a lower fatality rate than other heavy trucks in 83% of the lower 48 states. Due to the higher design standards, pavement damage costs are lowest on interstate highways as compared to other road types. Allowing state-legal, loaded log trucks access to federal interstate highways would improve the overall safety and efficiency of timber transportation and reduce pavement damage costs and CO₂ emissions within the study areas. Overall, the study findings suggest that allowing state-legal, loaded log trucks to operate on interstate highways would improve the safety and efficiency of timber transportation in Wisconsin and Minnesota.

KEYWORDS:

• Fatalities
• pavement damage
• traffic control structures
• gross vehicle weight (GVW)

Acknowledgements

The authors wish to thank Henry Schienebeck, Executive Director, Great Lakes Timber Professionals Association for his assistance in securing funding for the project, helping to shape the study focus and recruiting hauler participants; Dr Joseph Conrad, University of Georgia, for sharing information about a comparable study he conducted in the southeastern US; the many trucking business owners and drivers who permitted us to install trackers on their over-the-road log trucks; and the forest products companies that provided data for portions of the analysis.

Disclosure statement

No potential conflict of interest was reported by the author(s).

Additional information

Funding

This research was supported by the Forest Resources Association; the Timber Harvesting and Transportation Safety Foundation; the Great Lakes Timber Professionals Association; the Department of Forest Resources, University of Minnesota; and the Minnesota Agricultural Experiment Station under projects MN-42-072 and MN-42-117.