According to Haynes, he began laying out "plans for the construction of a mechanically propelled vehicle for use on highways" in 1891. His first idea was for a steam-powered vehicle, but after careful consideration he decided the use of a furnace on the device would be too dangerous. His second plan was to use electrical power, but after research he found that no practical means existed to store the electricity required for operation. He continued to develop his plans until the summer of 1893 when he attended the Chicago World's Fair, where he first witnessed a gasoline engine. The demonstration of the newly invented engine inspired him to decide that an internal combustion engine would be the most practical method to propel his vehicle. A gasoline-powered European automobile built by German inventor Karl Benz (who patented the first automobile in 1886) also was on display during the fair, although it is unknown if Haynes witnessed this vehicle during his visit.