cheez
Master Of The Darkside
I've seen these before but they are starting to become more common in their use; like a roundabout, if you haven't encountered one before they can be a bit confusing. I figured a post on BARF to encourage discussion and raise awareness wasn't a bad idea, being as the one on 120 near Manteca is about to open (or already has, I'm not sure.)
A Diverging Diamond Interchange works to decrease the amount of traffic which crosses other traffic. In a normal four-way interchange, there are 12 points of conflict which can arise- 3 directions of travel for each of four directions. The right turn traffic is merging with a traffic flow and is generally low risk for severe injury/accident as a result. The straight traffic is generally well controlled and has delays between each direction of travel change, allowing traffic to come to a stop. Left turns, however, introduce significant conflict with oncoming and cross traffic, and are the single most dangerous type of turn by severity of accident produced.
By eliminating the left turn conflict in the DDI interchange, the risk of severe injury accidents is decreased. As drivers approach the interchange, they have the option to turn right at the near-side road. They then proceed through a stoplight which crosses them over to the other side of the roadway, allowing those who need to turn left to do so in a protected manner resulting in a similar merge to the right turn. Traffic then crosses back over under another control signal, returning to 'normal' operation. This reduces the number of conflicts where traffic crosses other traffic from 8 to 4 by eliminating the left turn conflicts.
That's a lot of words. The video may explain it better.
youtu.be/-wnNi2O-Vos
(Mods, if this post belongs in a different forum, I humbly request you rehome it.)
A Diverging Diamond Interchange works to decrease the amount of traffic which crosses other traffic. In a normal four-way interchange, there are 12 points of conflict which can arise- 3 directions of travel for each of four directions. The right turn traffic is merging with a traffic flow and is generally low risk for severe injury/accident as a result. The straight traffic is generally well controlled and has delays between each direction of travel change, allowing traffic to come to a stop. Left turns, however, introduce significant conflict with oncoming and cross traffic, and are the single most dangerous type of turn by severity of accident produced.
By eliminating the left turn conflict in the DDI interchange, the risk of severe injury accidents is decreased. As drivers approach the interchange, they have the option to turn right at the near-side road. They then proceed through a stoplight which crosses them over to the other side of the roadway, allowing those who need to turn left to do so in a protected manner resulting in a similar merge to the right turn. Traffic then crosses back over under another control signal, returning to 'normal' operation. This reduces the number of conflicts where traffic crosses other traffic from 8 to 4 by eliminating the left turn conflicts.
That's a lot of words. The video may explain it better.
youtu.be/-wnNi2O-Vos
(Mods, if this post belongs in a different forum, I humbly request you rehome it.)