I suspect that any complaints were about the length of time spent in the queues for the traffic lights.
There is virtually no queue out of Marple at 7 am, and traffic flows freely at 30 miles per hour.
Returning at 4:30pm the queue is normally joined around the Wright's Arms, and crawls all the way to the bottom of Dan Bank from where it flows freely, at 30 miles per hour if you are lucky !, until Rose Hill, provoided you are not behind a bus.
I can accept that SMBC tinkering with the traffic light sequencing etc can increase the 'flow' of cars through the lights i.e the number of cars per hour.
I fail to see how altering the traffic lights can alter the 'speed' of the traffic i.e. miles per hour which is totally under the control of the driver.