OASDI stands for old age, survivor and disability insurance, which is more commonly referred to as Social Security. To pay for these programs, the federal government imposes a tax on earned income that must be withheld by your employer.
According to the December 1985 issue of Popular Mechanics, the Protex Safety Signal Company introduced flashing turn signals in 1920. The first modern turn signal, though, can be attributed to Edgar A. Walz, Jr. who, in 1925, secured a patent for one and tried to market it to major car manufacturers. They just weren't interested, and the patent expired fourteen years later. Meanwhile drivers and inventors kept working on other solutions.
Hazard lights are required to be activated when a driver parks a vehicle on a roadway during the period from 1/2 hour after sunset to 1/2 hour before sunrise or at any other time when conditions of poor visibility exist; or when the vehicle is travelling at less than 40 km/h due to vehicle impairment.