The Evolution of the Semi-Truck in the 20th Century

Bright red semi truck modern transportation on spectacular highw

If you’re not entirely sure what a semi-truck is, you’re probably wondering why its name implies that it’s only “half” of something! Well, any professional with dispatcher training can tell you that a semi-truck consists of a tractor and a half-trailer. While the half-trailer of a semi-truck actually only has back wheels and no front ones, the front of the semi is instead supported by the tractor. Today, these trucks are mainly used to transport goods and cargo by highway; however, there was once a time when driving semis was completely unregulated, and the super-highways they roll on now were totally non-existent. Read on to discover some of the highlights of the evolution of the semi-truck.

The Launch of the Semi-Truck

Graduates with dispatching training can confirm that the semi-truck was adopted as a result of a need for alternate modes of transporting cargo during World War I. To meet these demands, two truck manufacturers – White, and Mack – surfaced and began producing semi-trucks. By the early 20th Century over one million semis ruled the roads of America.

The “New Deal”

The “New Deal” was a series of domestic programs developed in the US during the Great Depression, in order to stabilize the economy and regulate industries. The American Highway Freight Association and the Federated Trucking Associations of America met to begin discussing a “code of completion,” which was quickly approved and passed in the summer of 1934. This was the first step toward regulating the trucking industry.

The Motor Carrier Act

In 1935, the code of completion was replaced by the Motor Carrier Act, which was passed to implement the hours of service regulation – this limited the driving hours of truck drivers. Though the hours were now regulated, by 1941 this issue of weight presented itself and had to be addressed.

Interstate Highway System

Once World War II ended, and the idea of creating “interstate highways” to support the substantial weight of trucks was authorized, finding  someone to fund these highways was a major obstacle to completing the project. Finally in 1956, the Interstate Highway System was sanctioned by the Federal-Aid Highway Act.
Experts who have completed their dispatch training in Ontario understand that the Interstate Highways System was built to connect a network of highways that allowed large, heavy trucks to pass through rural and urban areas at quick speeds. This system was able to accommodate trucks that weighed up to approximately 73, 000 lbs.

The Trouble with the Mississippi Valley

Though 1974 marked the Federal-Aid Highway Amendments’ establishment of a maximum vehicle weight of 80, 000 lbs., a minimum weight was not established. This caused some conflict with several states in the Mississippi Valley who refused to increase their interstate weight limits to 80, 000 lbs. This caused a major problem because semi-trucks were not able to cross these states – professionals in this field can confirm that these areas later became known as the “barrier states.”
In 1982, the trouble with Mississippi’s barrier states was swiftly resolved as the federal minimum weight limit for trucks was established by the Surface Transportation Assistance Act.
Which year do you think was the most important for semi-trucks in the 20th century?

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