Detail was conspicuously missing from the junction designs at Aggregate Industries' recent public exhibition; AI's traffic consultant couldn’t or wouldn't talk numbers.
The screenshot above is of the Birdcage Lane junction with the B3174 Exeter Road. The junction opens out to about 13m. Look at the set of designs below that AI put forward for its last application. The access road is 7.3m wide, making the junction around 35m at its widest point - almost 3x the width of the current Birdcage Lane junction.
AI claimed that its designs didn't need the removal of any additional trees or hedgerows. Quite how that's possible, given that the gateway next to the Public Footpath doesn't belong to AI, is anybody's guess.