without TPMS. Main findings are that TPMS fitment reliably prevents severe and dangerous underinflation and hence yields the desired effects for traffic safety, fuel consumption and emissions. The study also showed that there is no difference in effectiveness between dTPMS and iTPMS and that the TPMS reset function does not present a safety risk. Privacy concerns with direct TPMS Because each tire transmits a unique identifier, vehicles may be easily tracked using existing sensors along the roadway. This concern could be addressed by encrypting the radio communications from the sensors but such privacy provisions were not stipulated by the NHTSA. Heavy-duty vehicles U.S. National Highway Traffic Safety Administration regulations only apply to vehicles under 10,000 pounds. For heavy-duty vehicles (Classes 7 and 8, gross vehicle weight greater than 26,000 pounds), most of the above-mentioned systems don't work well, requiring the development of other systems. The US Department of Transportation has commissioned several studies to find systems that work on the heavy-duty market specifying some goals that were needed in this market. The SAE has tried to disseminate best practices since legal regulations for heavy vehicles has been lagging. Compulsory America The first country to have TPMS mandatory was the United States of America. In the early 2000s, numerous traffic accidents such as rollovers and tire blowouts occurred due to insufficient air pressure level. NHTSA regarded flat tires as a potential threat to safety which was soon followed by the enactment of the law on attaching TPMS for every vehicle in September 2007. South Korea TPMS became obligatory for every vehicle under 3.5t sold after 2013. Later in 2015, every vehicle had to have TPMS regardless of its size. In 2011, Hyundai Mobis successfully developed the TPMS and first applied it in the Veloster. As a result, the sensor's power usage is about 30% lower than that of existing products, reducing battery size and reducing sensor weight by more than 10%. Icons See also Central tire inflation system Cold inflation pressure Nira Dynamics AB Tire-pressure gauge Loose wheel nut indicator References External links Automatic identification and data capture Vehicle safety technologies Automotive technologies Tires