You might have to do / use animation for this, as someone who knows about 2D animation, you could try alternating between On & Off...
What I mean is -> oXo <- lets call the 1st light 1 and the 2nd light 2... 1 is black for 10 frames while 2 is lit for 10 frames... then you switch... 1 is lit for the next 10 frames while 2 is black... and so forth and so on... I'm not saying to use 10 frames mind you it's just an sample... That's just a rough idea based on 2D animation... Technicaly it'd be more like 24 frames w/ one off & the other on, then switch them over for the next 24 & so forth, or whatever frame rate you think would work or look best for your project... Now mind you I'm just basing this off of 2D animation cycles, not sure if Blender or 3D works the same way, hope this helps out