英语词源字典 - 在线词源网站

bumper (n.)[bumper 词源字典]: 1670s, "glass filled to the brim;" perhaps from notion of bumping as "large," or from a related sense of "booming" (see bump (v.)). Meaning "anything unusually large" is from 1759, slang. Agent-noun meaning "buffer of a car" is from 1839, American English, originally in reference to railway cars; 1901 of automobiles (in phrase bumper-to-bumper, in reference to a hypothetical situation; of actual traffic jams by 1908).[bumper etymology, bumper origin, 英语词源]
snarl (n.1): late 14c., "a snare, noose," from snarl (v.1). Meaning "a tangle, a knot" is first attested c. 1600. Meaning "a traffic jam" is from 1933.
traffic (n.): c. 1500, "trade, commerce," from Middle French trafique (15c.), from Italian traffico (14c.), from trafficare "carry on trade," of uncertain origin, perhaps from a Vulgar Latin *transfricare "to rub across," from Latin trans- "across" (see trans-) + fricare "to rub" (see friction), with the original sense of the Italian verb being "touch repeatedly, handle."

Or the second element may be an unexplained alteration of Latin facere "to make, do." Klein suggests ultimate derivation of the Italian word from Arabic tafriq "distribution." Meaning "people and vehicles coming and going" first recorded 1825. Traffic jam is 1917, ousting earlier traffic block (1895). Traffic circle is from 1938.