What is being described in Ayn Rand's, Anthem, when it says wagons which moved without horses?

They whisper many strange things, of the towers which rose to the sky, in those Unmentionable Times, and of the wagons which moved without horses, and of the lights which burned without flame.

In context, towers that rose to the sky are skyscrapers, wagons without horses are cars or truck, and lights that burned without flame are lightbulbs (electricity).