I found the following story on QI (series K, episode "Knees and Knockers").
Around the turn of the century when automobiles were becoming more commonplace, certain groups attempted to restrict automobiles' presence from motivations of either discomfort around the new technology or because they believed cars would threaten their jobs or some aspect of their lives.
In Pennsylvania, the Farmer's Anti-Automobile Association really pressured local government to keep cars OUT. As Pennsylvania is quite a rural, agrarian state, farmers said that cars spooked the livestock and traveled so fast that drivers kept running over chickens and hitting cows or horses.
I don't know if any of this ever made it into actual Pennsylvania law, but the Association ordered motorists to adhere to certain rules they made up about driving a car to make everything
as inconvenient as possible to the motorist as safe as possible for everyone.
1.) Automobiles traveling along country roads at night must send up a rocket every mile and then wait 10 minutes for the road to clear. The driver may then proceed with caution blowing his horn and shooting off roman candles.
2.) If the driver sees a team of horses approaching then the driver must stop, pull to one side of the road and cover the car with a blanket or dust cover which is painted or colored to blend into the scenery.
3.) If the horse is unwilling to pass an automobile on the road the driver must take the car apart as rapidly as possible and conceal the parts in the bushes.