Hello everyone
Some interesting points so far. If possible, I'd like to concentrate on discussing signal-controlled junctions, rather than drifting too far into the merits of strict liability.
I'd like to expand on my original post:
1. Signal-controlled and give-way junctions are two different things.What works well for one does not necessarily work well for the other. Traffic lights are used in situations where there are greater volumes of traffic turning in and out of a side road. Therefore requiring drivers to give way in this situation may be less safe and effective than elsewhere. It is also harder to make the priority really clear, and force slow speeds through design, at traffic light junctions.
2. Familiarity and expectationsJust because something is unfamiliar, doesn't mean it shouldn't be done. However, if you are changing something which will result in a lot of upheaval, you need to be sure that the thing which you are changing it to is really that much better, so that it is worth the upheaval. I'm not sure if continental-style traffic light junctions are a big enough improvement to justify the change.
Let's compare the changes resulting from a switch to this type of junction, versus the changes from introducing simultaneous green junctions. With the simultaneous green junction, nothing changes from the drivers' perspective, whereas with the "continental-style" junction, a change of behaviour is required. Traffic lights of the existing type have been in widespread use for a long time in the UK, so drivers may have quite fixed expectations. With the simultaneous green system, cyclists must get used to other cyclists approaching from all directions. However, since cycle-specific traffic lights are currently very rare, I do not think it would be a big problem to adapt to this. People have much less fixed expectations about this.
3. Different types of conflictAs I understand it, traffic light design is a compromise between separating conflicting movements, and extending the cycle time (and possibly reducing capacity). Within this, there are various possibilities for what conflicting movements to allow. All designs under discussion allow car/car conflicts. Existing UK junctions have no car/ped conflicts, and also do not allow car/bike or bike/bike conflicts where separate cycle infrastructure is provided. The "Continental-style" junction introduces car/ped and car/bike conflicts, although does not have bike/bike conflicts. The simultaneous green junction does not have car/ped or car/bike conflicts, but does allow bike/bike conflicts. To my mind, bike/bike conflicts are greatly to be preferred to car/bike or car/ped conflicts. Cyclists are likely to be able to move and negotiate past each other without colliding, and if they do the consequences will be less severe.
Notes1. "continental-style" is probably not a very good name. Nevertheless, everyone seems to get what I mean.
2. I have presumed that people know what "simultaneous green" means. Here is a very positive blog post about it:
http://www.aviewfromthecyclepath.com/se ... us%20greenMark Wagenbuur is a bit more skeptical:
https://bicycledutch.wordpress.com/2014 ... ling-city/