Traffic lights not on long enough

The junction at Paisley Road West and Dumbreck Road - the traffic signals on paisley road west go to green for approx 15 seconds, the traffic signals stay green for Dumbreck road for approx 1 minute and 13 seconds The traffic builds up on paisley road west and affects the bus lane and entrance to streets and garages, the lights are not on for long enough to clear effectively, the traffic at dumbreck road then blocks the slip road to M74/M8 therefore not a lot of traffic clears and its all left queuing up on paisley road west so even when the light is at green no cars can turn left causing more traffic build up Why is there such a disparity with the times of the green light, both roads are just as busy therefore it doesnt make sense why one green light stays on for approx 7 and a half times longer than the other one This needs to be looked at and amended so the green light stays on for longer from PRW and clears the traffic more efficiently