The whole sequence takes 16 seconds. [Step 1] From 0 - 4 seconds , G1 on , R1 off , G2 off , R2 on. [Step 2] From 5 - 7 seconds , G1 off , R1 on , G2 off , R2 on. [Step 3] From 8 - 12 seconds, G1 off , R1 on , G2 on , R2 off. [Step 4] From 13-15 seconds, G1 off, R1 on, G2 off , R2 on. This is a Traffic Roadwork question. This is my circuit and I cant understand which part of it went wrong , I made a K-map for G1 and G2 when they are on and implemented it onto my circuit then i simply inverted them to R1 and R2 respectively since when green is on, red must be off for a traffic. The flip flops are basically numbers from 0 to 15 so I know at which seconds they are currently at. Help would be appreciated if someone can point out to me where I made the mistakes.