Double Crossover Merging Interchange (DCMI)
The DCMI’s lane configuration and design provides a method of constructing a high capacity interchange with free-flow operations in a relatively small area, as opposed to the area needs of a full clover leaf interchange, or an interchange with flyovers. The DCMI uses a unique configuration of a main bridge with two minor side-bridges on either side of it. This allows traffic to crossover the opposing/conflicting traffic streams while eliminating weaving sections and resulting in a lane configuration with primarily merging sections. The DCMI has some of the characteristics of a relatively newer alternative intersection control called a DCD (Double Crossover Diamond), also referred to as a Diverging Diamond Interchange (DDI).
DCMI's Unique Features and Benefits
Although the DCMI incorporates some of the benefits of the DCD (Diverging Diamond), it has several new and novel components and resulting benefits not rendered by the DCD. The DCMI is able to provide free-flow operations while eliminating the need for traffic signals and/or weaving sections within the influence of the interchange. By employing two minor-bridges (grade separation) on either side of the main bridge the traffic signals can be removed. Moreover, the off-ramp traffic can be crossed over on the same minor bridges as the through and left turn traffic streams of the minor road. In turn, this eliminates conflicts that would occur with the at-grade traffic signal. The illustrations above depict this type of configurstion. The DCMI's unique configuration not only allows the elimination of the conflicts that occur at-grade, but also allows the off-ramp traffic to cross over without the need for lane changes or weaving within the interchange.