STOP! in the name of science...

Here's a photo from a driver's-eye view of the intersection, taken yesterday. As you can see, the vegetation on the left greatly reduces visibility compared to in winter:

The distance from the car position at the junction to the limit of visibility is 40m. At the posted speed limit of 60MPH (or 26.8m/second), that means you have exactly one and a half seconds between seeing a car and it crashing into you.

Now in a car you can (and I suspect most people do) 'floor it' to get out of the danger zone, sharpish. On a bike, with children, starting off on an uphill gradient and getting across into Nun's Walk in 1.5 seconds is highly unlikely.

This online stopping distance calculator tells us that at 40MPH, in the dry, the recommended stopping sight distance is 72m. At 60MPH the distance is 141m. It gets worse in the wet, and I haven't factored in the slight downhill gradient which again increases the stopping sight distance.

The Stopping Sight Distance is, according to Wikipedia, "the distance traveled while the vehicle driver perceives a situation requiring a stop, realizes that stopping is necessary, applies the brake, and comes to a stop".

Guess what speed would allow a driver of a car or HGV to see and avoid a collision? 30MPH. Yes, the extra 10MPH going from 30 to 40 nearly doubles the stopping distance.

What I believe this shows is that even under best-case conditions, assuming a driver is not pushing the speed limit, the stopping distance they need to see and avoid colliding with a vehicle or people on bikes at the intersection greatly exceeds the length of visible road.

This intersection is the stereotypical 'Accident Waiting To Happen'. Except in my view, it's only an 'accident' if you couldn't foresee it happening and couldn't do anything about it. A collision, injury or death here will not be an accident. It will be an omission to act in the face of known risks.

Meanwhile, I've had a response to my initial query from HCC. More to follow...