The requirements in the previous version of this standard established wiper durability based on the GVW of the vehicle with a cut-off at 11 800 kg (26 000 lb) GVW. The intention was to prescribe a greater durability requirement for over-the-road (OTR) trucks that have long life expectancy. This, however, meant that some low-mileage vocations such as recreational vehicles, fire apparatus, school buses, etc. would be held to the higher durability standard simply because of their GVW. Other vocations below 11 800 kg (26 000 lb) GVW would not require the higher durability even though their mileage life expectancy may be high. The standard has therefore been revised to recommend wiper durability based on the life expectancy of the vocation (in miles) rather than the GVW.