My attention was grabbed recently by an article in Transport Topics which stated that DOT was awarding funding for a heavier truck study. The article took me back to this time last year when the trucking industry was lobbying for the passage of the re-introduced Safe and Efficient Transportation Act (SETA). For several years now, the trucking industry has been lobbying for higher weight limits. Meanwhile, rail and law enforcement groups have opposed raising weight limits citing legitimate reasons such as public safety.
While the language raising weight limits in the SETA bill was removed by a 33-22 vote, DOT’s funding award is a proactive step towards determining the validity of each group’s arguments and laying the groundwork towards raising weight limits in the future.
Why is Raising Weight Limits a Big Deal?

As you already know, the amount of freight shipped throughout the U.S. continues to increase each year, spurred by population growth and the associated needs. However, as the nation recovers from The Great Recession, the amount of freight shipped will increase at a significantly accelerated rate in the next 10-15 years, almost doubling what it was in 2000. I do not need to mention the
obvious fact that road capacity is not increasing at the same rate.
This is very important for a number of reasons:
- While rail is often the first choice for transport, it is limited across the U.S. by the number of railway lines and their limited geographic reach within individual states – you simply cannot get freight everywhere by rail.
- To deliver the freight, current interstate weight limits force trucks to travel on rural state roads and pass schools and neighborhoods, jeopardizing safety in those areas. Raising weight limits would put these trucks on divided interstate highways where they can safely transport goods.
- The highest weight limit currently allowed in most states is up to 85,500 pounds on five axle trucks on state roads, which take longer to stop than the 97,000 pound six axle trucks that are being proposed – this has safety implications that directly impact state law enforcement.
- These same six axle trucks get better gas mileage carrying 97,000 pounds than what is currently on our nation’s interstates; in some studies up to 17 percent more ton-miles per gallon. This translates to a decrease in fuel consumption and a reduction of the greenhouse emissions being deposited.
- Raising weight limits would actually improve state highway infrastructure as fewer trucks would be necessary to satisfy the shipping needs. This would put less overall weight on any given stretch of interstate highway, while directing higher usage fees toward local bridge repair and maintenance.
- Current weight limits control the amount of payload that can be carried in a truck. An increase in vehicle weight limits would increase the allowable weight per trip. Freight transportation cost savings would benefit the shippers, carriers and end consumers.
It is important to note that raising weight limits will affect only the movement of heavier goods – which represents approximately 25 percent of freight that is currently being shipped.
While the details of the DOT study remain unclear, it is apparent that its purpose is to “determine if there are any associations between higher vehicle weights and motor carrier safety violations.” This will definitely be something to watch throughout the rest of the year and in 2013. It’s refreshing to see our politicians taking a proactive step in addressing our nation’s infrastructure needs. This study can only further prove the importance and benefit of raising weight limits across the country.







