Designing a revolutionary intersection like this will help eliminate accidents on highways

This diamond-shaped branch intersection is likely to be the solution for future transport networks.

After thousands of years of designing and building roads, you will think that today people are fully aware of the best road construction techniques. But in the past decade we have witnessed many innovations in this area in the United States. Since 2009, a new type of intersection has begun to sweep 22 states of this country and there are still many such works under construction.

Known as the "diamond-shaped branch intersection" (Diverging Diamond Interchange - DDI) , this new line arrangement is a smart tool to solve the most dangerous turns on any high-speed intersection. .

According to Carlos Sun, a construction and environmental engineer, "The power of the DDI deliveries lies in the ability to allow left-turn vehicles to not encounter the opposite lane as on regular intersections."

On normal intersections like this, vehicles that want to turn left are likely to bump into vehicles coming from the opposite direction or wait for red lights for a long time.

The left turns are not only dangerous, but also make the driver risk turning the vehicle at a 90-degree angle - certainly not effective. At busy intersecting roads, the driver constantly takes time at dense traffic lights to wait for those who want to turn left.

There are many diagrams that illustrate the new DDI layout, but in fact, you should understand that simply walking on DDI will be like this: you drive out from the right lane of the road. First, you wait for the red light for the cars coming from the opposite direction to move to the left lane. Then their side lights also turn red and it is your turn to turn to their left lane. The cars merge or split in the direction of small separate directions divided according to the drawing on the road. Meanwhile, a highway will be located on the upper floors of the above roads, allowing more traffic to pass through that area. Traveling between these roads has never been so easy.

Operation diagram of the new DDI interchange.

The person who laid the groundwork for this diamond intersection is a boy named Gilbert Chlewicki . As a graduate student in 2000, Chlewicki wrote an essay on a new type of traffic arrangement system. After that, he went to France and was surprised to see buses carrying tourists moving smoothly through a diamond intersection in the outskirts of Versailles. In fact, France has pioneered this transport system since the 1970s, but the DDI intersection is still considered Chlewicki's discovery because of his efforts to make it popular in the United States. So far, this type of intersection is extremely hot in states like Utah or Missouri, where people often have to travel long distances.

With the DDI interchange, the vehicles going from the south or north direction to turn left will follow the blue line, following the direction of the red arrow, without touching the vehicles facing the opposite lane.(Yellow line: where the cars stop waiting for the red light).

Last year, Sun and transportation experts from different countries formed an analytical team that compared the safety of DDI crossroads to traditional diamond design intersections. . See more explanation of DDI diamond intersection intersection in the video below:

Of the 7 intersections tested, 5 had significant improvements in safety. Overall, engineers concluded that the diamond-shaped branch intersection could reduce the accident rate by 33%. Possible accidents are quite mild and do not kill people. Heavy accidents at the critical level decreased by 60%. Property damage is reduced by 50%. Although these figures seem to be subjective, the researchers also realize that drivers almost never go wrong on these intersections. If they make mistakes - usually at night - the accidents are usually not heavy.

In the United States, this design method quickly received attention. Sun and colleagues said more research will be needed to confirm that this is the safest type of intersection, but the preliminary results have been very positive for both drivers. bicycle and pedestrian.