A diverging diamond interchange ddi, also called a double crossover diamond interchange. The ddi is currently under construction and will open this august at nw 27th avenue and this fall at nw 57th avenue. Marylands first diverging diamond interchange ddi opened to traffic at md 295 and arundel mills boulevard in anne arundel county in june 2012. Diverging diamond interchange minnesota department of. How the design can significantly improve traffic operations. This article is not specifically about the diverging diamond interchange, but raises another topic related to innovative geometric interchanges. The diverging diamond is based on the idea that if you can eliminate the need for leftturn arrows, then signals will have maximum efficiency, fewer conflict points, and be able to serve more traffic with better safety and less congestion. Exhibit 22 and exhibit 23 are two examples of using video animation to. Its called a diverging diamond interchange ddi, which will. This new interchange is planned to be the entrance to the rental car facility for bwi airport. Here are some questions and answers to help you understand this better. Nexus ddi the dynamic design solution for diverging.
Interchanges are designed to fit specific local conditions and meet driver expectations. While the ramp configuration is similar to a traditional diamond interchange, traffic on the crossroad moves to the left side of the roadway for the segment between signalized ramp intersections. Nexus ddi the dynamic design solution for diverging diamond interchanges recorded introducing nexus ddi a welldesigned diverging diamond interchange has the potential to improve safety and reduce traffic delays more effectively, and at a lower cost, than traditional interchanges. The ddi alternative is will improve traffic conditions at the i590winton road intersection. Its a nontraditional design to accommodate leftturning movements at. Diverging diamond interchange ddi february 25, 2019 coming to a highway near you. A diagram illustrating traffic movements in the interchange plan of rejected diverging diamond interchange in findlay, ohio. The ddi provides a crucial link to the maryland live. As of 20, all ddi crossovers constructed in utah have.
Motorists drive through the diverging diamond interchanges ddi on the left side of the road, which converts all turns into reduced conflict curbside turns. Road interchange was reshaped into a diverging diamond interchange ddi. The ddi resembles a conventional diamond interchange, which is the most common form in the united states. This innovative interchange, sometimes called a double crossover diamond, is. Crossover points serve traffic in two directions and require two stoplights. The first ddi was constructed a decade ago in springfield, missouri. To turn right from a freeway ramp, use the rightturn lane like at a conventional diamond interchange h to turn left from a freeway ramp, follow lane markings and traffic signals to stay on the left side of the arterial, and then cross to the right side after passing through the interchange. The ramp formation is similar to a traditional diamond interchange common in texas. Diverging diamond interchange benefits innovative ddi interchange comes to ankeny a new intersection design known as a diverging diamond interchange ddi, or double crossover diamond interchange, takes traffic safety and efficiency to a new level.
Pdf analyzing the diverging diamond interchange using. Observations of pedestrian behavior and facilities at. Diverging diamond interchange an alternative to the conventional diamond interchange or other alternative interchange forms. The simulator for active distracted driving sadd podcasts. As one of the most popular unconventional interchange designs, diverging diamond intersection ddi has received increased attention over the past decade. Subscribe for updates about civil fx vision, a better 3d visualization tool for civil engineers. Driver expectation ddis relocate through and leftturn movements at the. Example video of diverging diamond interchange ddi that exists. It is unusual in that it requires traffic on the highway overpass to briefly drive on the opposite side of the road from. A diverging diamond interchange ddi, also called a double crossover diamond interchange dcd, is a type of diamond interchange in which the two directions of traffic on the nonfreeway road cross to the opposite side on both sides of the bridge at the freeway. Ashford dunwoody and interstate 285 diverging diamond interchange visualization duration.
We offer many excellent opportunities for you to take a more interactive approach in learning about our solutions. Both designs have the same number of merging and diverging conflicts. The nations first ddi was built by modot in springfield in 2009. To turn right onto a freeway ramp from the arterial, use the rightturn lane like at a conventional diamond interchange a to continue straight on the arterial, follow lane markings and traffic signals to cross to the left side of the arterial, and then cross to the right side after passing through the interchange h. Two phase traffic signals are installed at the roadway crossover points. Fhwa diverging diamond interchange informational guide. As one of the most popular unconventional interchange designs, diverging diamond intersection ddi. A diverging diamond interchange ddi is a type of interchange in which the two directions of traffic on a nonhighway road cross to the opposite side on both sides of a bridge.
A website that explains the unconventional and innovative interchange design called the diverging diamond interchange or ddi. A diverging diamond interchange ddi, also known as a double crossover diamond dcd, is a diamond interchange that crosses traffic to the opposite side of the road across an interchange so vehicles have unimpeded movement onto the freeway ramps. Why the design is considered a safer design than other diamond interchange. The typical diamond interchange hosts 26 of these points because each stream of traffic crosses at every artery. What traffic innovation was featured in time magazines feb. The ddi was not selected as the chosen alternative because state officials did not want the first ddi in maryland to go in a location where there would be a lot of unfamiliar drivers. Opened in 2014, the i69dupont road ddi was the first ddi in the state. I69 and dupont road diverging diamond interchange burgess. What i do is put the highway access between the two lanes, to avoid the crossover and allow traffic to bypass the interchange around the outside, but it means right turns are. Design and construction of highway pavement joint systems complex joint layouts. Important considerations for when and how to design a diverging diamond interchange presented by. Wisdot is considering the use of a diverging diamond interchange ddi at key. This animation shows how diverging diamond interchanges help keep traffic flowing.
A diverging diamond interchange ddi, also called a double crossover diamond interchange dcd, is a type of diamond interchange in which the two directions of traffic on the non freeway road cross to the opposite side on both sides of the bridge at the freeway. Many people dont understand the purpose of the diverging diamond interchange. This is a special form of the standard diamond interchange where the thru lanes of the cross street cross each other twice. Traffic engineers predominantly use one of those tools to analyze a diverging diamond interchange ddi, also known as double crossover diamond interchange. An insightful solution to your ddi design highways are shifting to more and more ddis and a welldesigned ddi has the potential to improve safety, reduce traffic delays, and save costs over traditional interchanges.
Government assumes no liability for the use of the information contained in this document. An innovative traffic design, noted as the first of its kind in california, is coming to the city of manteca. Animation of diverging diamond interchange under construction at elmhurst road on interstate 90 near elk grove, illinois, to be completed in 2016. Observations of pedestrian behavior and facilities at diverging diamond. Diverging diamond interchange at i55 and weber road duration. The diverging diamond interchange is coming to a road near you.
Nov 29, 2011 this is how you drive through a diverging diamond interchange. Abstract with a recent push towards innovative solutions in interchange design, the diverging diamond interchange has been the next big thing. Figure 2 shows conflict points for a 4lane ddi interchange in the upper panel and for a conventional diamond interchange in the lower panel. Nov 08, 2011 the diverging diamond is a design that moves cars quickly across a freeway without building an expensive cloverleaf exchange, while at the same time providing accommodation to noncar transport. Wisdot is considering the use of a diverging diamond interchange ddi at key highway interchanges across the state. Diverging diamond interchange and double crossover. The only problem with that type of interchange, as i see it, is that it needs three levels, or a traffic light on either side. In the united states, more than 90 ddis have been constructed in 29 states since 2009. A fdot animation of a diverging diamond intersection at i10 and nine mile road is below. Based on the traffic modeling and traffic analysis, this alternative meets the project objectives and is. However, traffic on the cross street switches to the left side of the roadway before the signalized.
The diverging diamond interchange ddi is an innovative new concept being pursued as an alternative interchange type that may provide a significant increase in capacity while actually reducing. A ddi is a diamond interchange on which the two directions of traffic on the cross street above or. For the past several decades, even the mere mention of considering left exits or entrances on highways, would. It has economically reduced congestion at key interchanges by improving safety and mobility to and. Diverging diamond interchange visualization youtube. While the ramp configuration is similar to a traditional diamond interchange, traffic on the crossroad moves to the left side of the roadway for. Development of a signal optimization model for diverging. Wisconsin department of transportation diverging diamond. Welcome to the official website of the diverging diamond interchange. A ddi is different from a conventional diamond interchange directional crossovers on either side of the interchange. We developed a 3d animation of a diverging diamond interchange in reno, nv. Diverging diamond interchange animation illinois dot if youre curious to see how a ddi works, watch this video from the illinois department of transportation idot.
Interesting elements archives diverging diamond interchange. Studies have analyzed various roadsigns to reduce similar driver errors. Instructional video on how to drive in a diverging diamond interchange. A ddi creates a diamond shaped pattern in the intersection and temporarily shifts traffic to the left side of the roadway prior to entering the intersection. Highways are shifting to more and more ddis and a welldesigned ddi has the potential to improve safety, reduce traffic delays, and save costs.
Department of transportation in the interest of information exchange. Diverging diamond interchange ddi figure 3 shows the layout of the diverging diamond interchange design. Californias first diverging diamond interchange coming to. Mar 10, 2011 instructional video on how to drive in a diverging diamond interchange. Diverging diamond interchanges ddi are diamond interchanges that more efficiently handle heavy leftturn movements.
Important considerations for when and how to design a. Mixeduse, transitoriented developments will benefit from these unconventional, innovative, alternative intersection designs. Diverging diamond interchange description a diverging diamond interchange ddi is a new freeway crossstreet design that handles heavy leftturn movements. Diverging diamond interchanges first ddi opened in springfield, missouri in. Diverging diamond interchange ddi in odense, denmark. Its a traffic design engineers say will reduce collisions and improve traffic flow along highway 120 and union road in. The diverging diamond interchange or ddi for short is a new interchange design. The diverging diamond interchange is an abomination. Development of a signal optimization model for diverging diamond interchange xianfeng yang1. Aug 29, 2014 northern utahs first diverging diamond interchange at 1100 south and i15 in brigham city is designed to improve traffic flow and safety, and help you get where youre going faster.
Two of its key weak points involve interchanges with heavy. Although these tools have shown great promise, they are expensive and the data collection and input setup is time consuming and resource intensive. Key wordsdiverging diamond interchange, ddi, alternative interchange, double crossover diamond, and dcd. The offramps have two leftturn lanes and one rightturn lane. Work is underway to create californias first diverging diamond interchange. There are some topics in the transportation world that are just not dared to be brought up. New york is joining the ranks of other states that is building a diverging diamond interchange ddi. For median uturn crossovers located on the major road, drivers turn left off the major road by passing through the intersection, making a uturn at the crossover, and turning right at the cross road. A diverging diamond interchange ddi is a type of diamond interchange in which the two directions of traffic on the nonfreeway road cross to the opposite side on both sides of the bridge at the freeway. Design and construction of highway pavement joint systems.
Though a relative rarity in the united states, it is gaining popularity because of its efficiency and safety. Diverging diamond interchange informational guide fhwa safety. In fort wayne, indiana, a traditional diamond interchange at i69dupont road was. Innovative, alternative intersections are often able to reduce traffic congestion in affordable, sustainable ways. A ddi is a diamond interchange on which the two directions of traffic on the cross street above or below the freeway cross to the opposite side on both sides of the bridge at the freeway. Motorists drive through the diverging diamond interchanges ddi on the left side of the road, which converts all. Maneuvering a diverging diamond interchange in jordan jordan independent, oct. Diamond interchanges missouri department of transportation.
Diverging diamond interchange primer mike on traffic. Noticethis document is disseminated under the sponsorship of the u. As of 20, ddis have been constructed in five utah locations and have been evaluated for design or construction in several more. Diverging diamond interchange animation illinois dot on. Diverging diamond interchange ddi the diverging diamond interchange or ddi for short is a new interchange design that will improve the flow of traffic entering and exiting the sr 836dolphin expressway. Pdf diverging diamond interchange signal phasing scheme. If youre curious to see how a ddi works, watch this video from the illinois department of transportation idot. Recently idot constructed a ddi at i88 and diverging diamond interchange animation illinois dot on vimeo. A ddi is an innovative design solution that addresses congestion by allowing vehicles to travel more quickly through an intersection.
This ddi s design is similar to what is being planned for i17 and happy valley road. The key to what makes a ddi work so well is how left turns are handled. Overall, the ddi has proven effective in the right circumstances. In a threelevel diamond interchange, the cross street is built in a third level with free flowing traffic as. From webinars to workshops, find what you need here. One such innovative design is the diverging diamond interchange ddi. Median uturn crossovers eliminate left turns at intersections and move them to median crossovers beyond the intersection. Its a nontraditional design to accommodate leftturning movements at signalized, grade separated interchanges while eliminating the need for leftturn phasing of the traffic signals also known as a double crossover diamond dcd.
Scott wolf, pe, pls 14th annual acecky fhwa kytc partnering conference august 11th, 2009. Two in springfield, mo route at i44 and national ave. What was one of popular sciences top 100 innovations for 2009. Recently idot constructed a ddi at i88 and route 59 near chicago. Important considerations for when and how to design a diverging diamond interchange. There are two onramps and two offramps that connect the crossroad and the freeway. The diverging diamond interchange ddi can improve traffic flow by limiting the number of phases in the traffic signals and improve safety by eliminating left turns. This innovative interchange is a lower cost transportation solution that adds traffic capacity to support area development. This innovative interchange, sometimes called a double crossover diamond, is designed to intuitively guide motorists through the pathways. To increase capacity and relieve traffic congestion, the i69dupont road interchange was reshaped into a diverging diamond interchange ddi. Intersection safety safety federal highway administration. You can be prepared for the ddi by viewing the animation video link below.
Drivers evaluation of the diverging diamond interchange. The microsimulation software chosen is described in detail, and the. Comparison of diverging diamond interchange and partial. Diverging diamond interchange animation illinois dot. Fourway interchanges, by comparison, host up to eight traffic paths. Many designs, while serving more vehicles, have traffic calming, are bike and pedestrian friendly, and create a platform for placemaking catalytic change. This animation shows how to drive a diverging diamond interchange. A diverging diamond interchange ddi, also called a double crossover diamond interchange dcd, 1 2 is a type of diamond interchange in which the two directions of traffic on the nonfreeway road cross to the opposite side on both sides of the bridge at the freeway. Here, you can learn all about the diverging diamond interchange including.