First click on one road segment, then hold down the <Ctrl> key while you click on the junction you want to disconnect from. Now they should both be highlighted and the Edit panel will give you the option "Disconnect road from node"
First click on one road segment, then hold down the <Ctrl> key while you click on the junction you want to disconnect from. Now they should both be highlighted and the Edit panel will give you the option "Disconnect road from node"