presents

The History of School Transportation in Mercer County, WV

Technical Information: Deciphering VINs

Overview

When studying motor vehicles (or piecing together information about a historical vehicle fleet, as is the case here), there are few bits of technical information more significant than the vehicle identification number, or VIN.

On a school bus (or any specialized truck or bus built in the same way), the VIN will usually contain information about the following qualities:

The manufacturer of the chassis.
The chassis model or series number.
The engine.
The gross vehicle weight rating.
Whether the vehicle is equipped with hydraulic or air brakes.
The body length and capacity (sometimes).
The model year.
The chassis assembly plant.
The vehicle's planned production sequence.
Whether the vehicle was produced early or late in the model year.

The VIN will usually not contain any of the following information:

The manufacturer of the body (unless the body and chassis manufacturers have an exclusive arrangement, or the body and chassis have been produced as an integral unit).
The transmission.
The wheelbase.
The restraint system (although this is encoded within the VIN of passenger cars).
The build year (which often deviates from the model year, especially on newer buses).
Any personally-identifiable information, such as the owner's name.

Nevertheless, these identifiers are the closest things to vehicular "DNA strings" that exist. Manufacturers use VINs to quantify production, while registration agencies and insurers rely on the numbers to track and identify vehicles.

History

In spite of what information regurgitated throughout the web might say, VINs did not "begin in 1954." Serial numbers of various kinds have existed on motor vehicles from the dawn of time; initially on engines, and later on frames.

For years, these were referred to as a bunch of things: Chassis numbers, frame numbers, car numbers, vehicle numbers, warranty numbers, serial numbers. The term "vehicle identification number" or "VIN" appears to have been standardized and popularized at the dawn of the 1970s; not coincidentally, after U.S. federal vehicle standards came into effect stipulating that the serial appear in standardized locations and be referred to as such.

Since the 1981 model year, VINs have had a standardized 17-digit format on vehicles sold in most North American and European markets.

In detail

Although ample information about passenger-car VINs exists in books and on the web, detailed information about heavier vehicles is tough to come by. These pages are very much a "work in progress," based on observations more often than not: