Adler Alternate Flashing Relay
date: label: date made
content: 1920s
label: date made
content: ca. 1920s
notes: label: Description
content: Automobile traffic increased significantly in the early 20th century, and so did collisions between cars and trains. Railroad companies installed warning signs and bells at crossings, but drivers ignored the signs, and motor noise drowned out the bells. Charles Adler, Jr., an inventor of traffic safety devices, tried signs that moved to attract the driver's attention. His 1921 STOP signal turned toward motorists when a train was approaching. In 1922, the Association of American Railroads chose a different signal—a pair of alternating flashing red lights—as the national standard. Adler devised a relay to create the alternating light pattern, and it was used by more than 40 railroads.
label: Location
content: Currently not on view
setName: label: See more items in
content: Work and Industry: Transportation, Road
label: See more items in
content: Transportation
label: See more items in
content: Road Transportation
creditLine: label: Credit Line
content: Amalie Adler Ascher
dataSource: label: Data Source
content: National Museum of American History
identifier: label: ID Number
content: 1989.0745.41
label: accession number
content: 1989.0745
label: catalog number
content: 1989.0745.41
label: model number
content: B400
objectType: label: Object Name
content: flashing relay