"Collision Course": sightlines and geometry of 4-way intersection in UK

[kurumi]

https://beyondthekerb.org.uk/collision-course/

Interesting discussion about the particular geometry of an otherwise modest-looking 4-way intersection.

Take a look at this plan view of a Vauxhall Zafira... When the driver looks towards the horizon, the front pillar will obscure some of the view. The red ellipse represents an approximate cross section at that point, with the shaded area beyond it being obscured as a result.

Once you extrapolate that obscured area, the extent of its effect is obvious. Here's the same set of lines drawn on the Zafira, scaled up and overlaid on Ipley Cross.

At the position shown, approximately 100m from the junction at Ipley Cross, the pillar obscures roughly 12m of Beaulieu road. That's six bicycle lengths: enough to hide not just a cyclist but a small group of riders.

Of course, as the driver approaches that junction, that obscured section of road moves towards the junction with them. As does the cyclist.

[kphoger]

With this design, no longer would it be reasonably possible for any driver to simply blow through the junction. Drivers would have to come almost to a stop.

This design would, very simply, force the slowing down that eliminates the problem of CBDR.

Where's |tradephoric|, saying that it wouldn't actually force anyone to slow down?

[EJumean]

I recall watching a Youtube video about this very intersection. For a while, they actually added stop signs (which, for the UK is extremely unusual, they are almost never seen, unlike Give Way signs). It has since been modified again and the Give Way signs returned.

Here's the video if anyone is interested.

https://www.youtube.com/watch?v=SYeeTvitvFU

[kphoger]

I recall watching a Youtube video about this very intersection. For a while, they actually added stop signs (which, for the UK is extremely unusual, they are almost never seen, unlike Give Way signs). It has since been modified again and the Give Way signs returned.

Here's the video if anyone is interested.

https://www.youtube.com/watch?v=SYeeTvitvFU

Aw, geez.  I watched that video too, and I didn't realize they were the same intersection.

[Scott5114]

It sounds like the problem is that British people handle stop signs approximately as well as Americans handle roundabouts.

The American solution would be to put a stop sign there and put a flag on it. Include some "stop ahead" signs and transverse rumble strips too. If people still run the stop sign, have the sheriff's deputy sitting there handing out tickets like candy until the problem stops.