Major road: Running up-down
Minor road: Running left-right
My idea for a new at-grade intersection design is called the double-crossover. I thought of it in 2020 and modeled it in April 2022.
This intersection can handle increased volumes of traffic by staggering yield points, so certain traffic only has to give way to one direction of conflicting traffic at a time, or not at all.
The design of the double-crossover is intended to be unsignalized and controlled with yield signs at the appropriate points, but it is possible to modify the design with a central traffic signal (or even signals on the edges as is common in the continuous flow intersection / displaced left turn). If the central traffic signal exists, it can operate in only two phases, saving time, wear-and-tear, and emissions.
At a normal four-way intersection with a major road and a minor road, traffic on the minor road which has the ability to proceed in any direction must give way not only to the major road, but also to oncoming traffic from the opposing direction of the minor road. This is particularly the case with left turns from the minor road onto the major road.
At the double-crossover, traffic on the minor road swaps the side of the road it is on prior to reaching the intersection. This allows through and left movements to be able to be accomplished without conflict with opposing traffic. Right turns are handled via a free slip lane which can merge onto the major road, or become an added lane.
Through traffic on the major road may proceed with priority throughout the design. Left turns from the major road onto the minor road are handled by having left-turning traffic get on the left side of oncoming traffic prior to the intersection, and then joining the minor road via either a merge or an added lane. Minor road traffic at this point is swapped back over to the right side of the road. Right turns from the major road are also handled via a free slip lane to the minor road.
This design as described above can be an alternative to the four-way stop, adding a 4+-phase signal, or other intersection type including the S-median which is often used when it is difficult or dangerous for traffic on the minor road to turn left onto the major road. Assuming the non-signalized implementation, maintenance costs are lower in that no electric control is needed, but signals can be added where deemed necessary should traffic volumes dictate it, and this newly-signalized intersection would be able to handle more traffic than a conventional one.