Chlewicki (2010) introduced a paper with theories on how the DDI works by examining the signal progressions both within the interchange and outside of the interchange. Chlewicki examined the unique traffic pattern within the interchange to make the interchange more effective. He also examines the unique traffic pattern that is established beyond the interchange at subsequent signals to increase the overall efficiency of the traffic progression for the entire corridor. This research determined that several factors play into synchronizing any two signals in the DDI, which are the space between signals, the speed of the vehicles, the cycle lengths, and the phase distribution. The procedure suggested by this research in designing a DDI was to (1) Lay out a rough schematic of DDI, (2) Determine cycle splits at each signal in the interchange for the design year during peak periods, (3) Determine the basic synchronization strategy based on turning movement volumes and consider the cycle length needs, (4) Determine how much time would be ideal to get from the first signal to the second signal, (5) Adjust speed and the distance between the crossover signals to optimize synchronization, (6) Make slight adjustments as necessary to signal timing to maximize the optimization, (7) Lay out signal along the corridor adjacent to the DDI and re-examine the cycle lengths based on the whole system and (8) Make adjustments as needed. Chlewicki states that
determining the correct cycle length can significantly increase the amount of bandwidth in both direction of the progression and that taking the signal timing into consideration during design can make an effective design even better.