Horse-and-buggy Amish now number over 200,000, with communities in 25 states plus Ontario.
As the Amish continue their high rate of growth–doubling about once every 20 years–traffic safety will become an even greater issue.
The Amish generally try to make themselves visible on the road–by installing orange signs, reflectors, as well as electrically-powered lights and blinker systems on their carriages. Some of this can get quite elaborate, hence the Christmas tree comparison in this L.A. Times article (no longer online).
Some of the more conservative sects have resisted, however. The Swartzentruber Amish forgo buggy lighting and even the standard orange slow-moving vehicle triangle, instead using lanterns and less-visible gray reflectorized tape.
This has been an issue in the past, resulting in a number of court cases involving conservative Amish groups.
Though buggies usually come out on the losing end in traffic accidents, most Amish sensibly recognize that it’s not only their safety that is at stake.