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.
But the idea was proposed (sort of) in 1916 when C. H. Thomas of Norristown, PA, wrote to Popular Mechanics describing an invention -- a battery and electric bulb attached to a glove so drivers could see hand signals at night. Flashing turn signals were first offered as an option by Buick in 1938, but only as rear flashing lights. In 1940 the flashing signal was extended to front lights, and the signal switch was given a self-canceling feature. Austin had a different approach to signal lights. When the signal lever was activated by the steering column, a lighted lever popped out of either side of the B-pillar indicating the direction of turning.