The defendant on a ticket issued for an overweight violation can be the operator or the carrier. The fines for an overweight violation depend on several factors.  The fines are a set amount per thousand pounds overweight, and vary depending the amount of the overweight. It also depends if the vehicle is operating on a permit, and how many overweight tickets the defendant has been convicted of in the last 12 months.

There are several ways a vehicle can be overweight; such as over the registered weight, over tire limits, over an axle weight, or over gross weight.  Depending on which way a vehicle is overweight depends on what there is for a enforcement tolerance.  Depending on the weight violation, a tolerance will vary from a zero tolerance to a 10% tolerance.  It also depends on whether the vehicle is being operated in conformance with a special permit.  However, there is no weight statute that uses the Gross Vehicle Weight Rating (GVWR) as the basis for a vehicle’s legal weight limit.

A scan tool with generic OBD II capability is necessary to perform the required check. A scan tool is a very useful device which is commonly used to assist in the diagnosis and repair of a variety of vehicle problems. Many inspection stations already own scan tools which can also be used to perform the required OBD check, but those inspection stations which do not will need to have one in order to inspect 1996 and newer vehicles. At a minimum, scan tools must be capable of :

To get a USDOT number, new applicants must register online via the Unified Registration System. 

In general, a USDOT Number is required if you are operating in interstate commerce and:

You have vehicles that are over 10,000 lbs.
You transport between 9 and 15 passengers (including the driver) for compensation, whether direct or indirect
You transport 16 or more passengers
You haul hazardous materials