First off, what is an overweight vehicle. There are pecial rules and regulations in place for vehicles, and based on their weights and axle loads, these too change drastically. There are various vehicles that are used for construction and agriculture which are over the legal weight limits and these must be transported from one place to the other rather than driven as the normal tar roads cannot handle their weight distribution. Make sure to check your local area rules and regulations on this matter before purchasing a vehicle. For such a vehicle which is over the legal weight limits, one needs to obtain an overweight permit. Here is how and why you may do so.
Need an overweight permit or not?
There is something known as the VAI or the Vehicle Axle Index. This is an equation through which one can measure the maximum ratio of actual axle weight against the reference axle weight. There are specific definitions and values based on the different VAIs for vehicles as well as regulations in place for their use and transportation. Most agricultural vehicles exceed this maximum level and thus require a permit to be used. Their unequally distributed loads mean that they have a higher chance of damaging the roads even with or agricultural rubber tracks on rather than the traditional wheel system, and hence the reason for these strict regulations. If you do not know how to calculate the VAI index for your vehicle, it is best to check with the regulatory bodies before purchasing of one. Again, the rules and regulations for these vehicles change from region to region and thus, a permit may not even be needed in some areas of the world.
What makes a Vehicle Suitable for an Overheavy License?
The main reason why a vehicle would require an overheavy license is the fact that it has indivisible loads. Thus, a vehicle which is not resounding an isolatable load and the VAI of the vehicle is either less or equal to that of the limit are automatically eligible to obtaining an overheavy permit.
Different Types of Overweight Permits
Based on the number of trips one makes, there are different overweight permits for different regions. A single trip permit will last the duration of a week and is only applicable for vehicles travelling from one destination to the other. For multiple trip permits, it is not limited to one destination but from a single origin to a given destination and lasts a whole month. Continuous permits are given for a period of two years and is limited to a radius from the core operating center of the vehicle. An area permit is one that is defined for a given road network or geographical area.