SoundCloud consistently starts playing related tracks or the next playlist once it reaches the end of the currently running playlist. Is there any way to stop that behavior from happening?
SoundCloud doesn't have any option to disable continuous play. Therefore you need to install a browser extension.
I have been switching back to classic mode before launching playlists. I only have to click "Switch back to classic" from the wrench menu in the top right of the site.
Update with new solution: The layout has considerably changed since this question was asked. There is now a little playlist button at most bottom left corner next to the current track. Once clicked, it brings a menu of the playlist/queue and a large button to switch on or off autoplay.