It's one thing to take a leisurely ride in a buggy on a rural road, that's where most Amish live and play. It's another thing to see buggies navigating bumper to bumper traffic. There are risks to sharing the road with buggies in each type of conditions. On a rural road with "no other cars on it", a car driver can have a tendency to be lulled into this "I've got the road to myself" attitude and just start motoring along at warp speed and by the time they crest a hill at 50 mph (on a road marked 35mph) and see a slow-moving buggy it's too late. Many tragic car-buggy crashes have resulted from that type of inattention. On the other hand, bringing a buggy into a congested city setting can spook the horse with all the car commotion nearby and that can be just as deadly. I've seen buggies increasingly navigating big city traffic (Lancaster, PA; New Haven, Indiana; South Bend, Indiana, etc) and this combination creates its own issues.
This photo shows a classic combination: a hulking yellow school bus, typical soccer Mom SUVs, a vintage 1950s Dodge, and a buggy all jockeying for position on congested Route 30 just outside of Lancaster, PA. The Amish driver seems to be taking the traffic in stride. The best advice I can give if you find yourself bumper to bumper with a buggy is: don't honk your horn for any reason if at all possible. That's the most often given advice to me when I talk to Amish buggy drivers about annoyances they have with cars are horn-honkers, the sharp, sudden noise can spook a horse and believe me you don't want that in heavy traffic.