200 cars seems rather high given the houses being built.
If I've counted up correctly, there's 35 houses being built. According to the 2011 census, there were 12 cars for every 10 households, so an average of 1.2 cars per household. (It looks like the figures are lower on average in the North West, but I can't easily find the figures on the ONS webpage I am looking at [1] so let's go with the national ones). That suggests there will be 42 cars on the estate. But let's round up to 50 because they are family homes - there could be a higher rate.
50 cars going off in the morning, 50 cars going back. 100 extra journeys on Hibbert Lane a day. That assumes - of course - that the cars are moving. And that's not guaranteed. I own a car and it gets used twice times a week, usually outside peak times. I do not commute using my car. It's a very expensive lump of metal to own...
I am sure Hibbert Lane will absorb the additional vehicle movements easily enough.
As for the traffic lights, well given how often I see traffic backing up on Hibbert Lane, I do wonder if things could be better. But equally have to ask, would changing the lights just make traffic back up onto Stockport Road instead?
One guaranteed cure is that we all decide to use our cars less!
[1] -
https://www.ons.gov.uk/peoplepopulationandcommunity/populationandmigration/populationestimates/bulletins/2011censuskeystatisticsforenglandandwales/2012-12-11#car-or-van-availability
