GRAVES MILL ROAD CORRIDOR STUDY
INNOVATIVE INTERCHANGES
Navigating a Diverging Diamond Interchange (DDI)
Priority III Projects: DDI at US 501 Building on Priority II Projects, these recommendedINNOVATIVE improvements will be needed if a INTERCHANGES
Navigating a Diverging Diamond Interchange (DDI) To turn right from a
maximum buildout and growth scenario occurs along the corridor. Priority III projects should be monitored over time as conditions dictate.
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To turn right onto aInterchange (DDI) Diverging Diamond
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Ǧ Depending on their level of comfort, cyclists may navigate the intersection using vehicle or pedestrian paths from a freeway ramp, Ǧ Depending on their level of comfort, cyclists may navigate the intersection markings and traffic signals using vehicle or pedestrian paths
To turn left freeway ramp from the What are the benefits of a DDI? follow lane arterial, use the right-turn ▪▪ Improved safety: Reduces the number of points where vehicles may cross paths to stay on the left side of the arterial, ▪▪ Increasedlane efficiency: Crossovers can operate with only two traffic signal phases, which like at a conventional use marked to the right side after allows the interchange to handle a greater volume of traffic and operate with less delayand then cross Pedestrians diamond interchange to safely ▪▪ Easier access to freeway: Design allows traffic to enter and exit the freeway without passing throughcrosswalks the interchange navigate the interchange crossing opposing lanes of traffic ▪▪ Cost effective: Since there are no left-turn lanes on the arterial, a DDI can have a narrower cross section and may be more cost effective than a retrofit or new NOT TO SCALE interchange construction
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Pedestrians use marked crosswalks to safely navigate the interchange
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freeway ramp, use the continue straight onright-turn the äToarterial, lane like at a follow lane markings conventional diamond and traffic signals to cross to continue straight on the left side of the arterial, ätheToarterial, interchange follow lane markings
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To turn left onto a freeway ramp from the arterial, follow lane markings and To turn left onto a freeway traffic signals to cross to the ramp from thearterial, arterial,and left side of the follow lane then turn leftmarkings onto theand ramp traffic signals to cross to the left side of the arterial, and then turn left onto the ramp
and then cross to the right andafter trafficpassing signalsthrough to cross to side the left side of the arterial, the interchange and then to the right Note: Forcross simplicity, only two directions of traffic side after passing through are shown. Opposing traffic follows similar routes. the interchange
Visit www.virginiadot.org/innovativeintersections to learn more.
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Concept at US 501 Interchange
▪▪ Preliminary results suggest the DDI offers the greatest reduction in delay and queuing, when compared to more conventional designs. ▪▪ Would likely be implemented when the Graves Mill Road / US 501 interchange bridge needs replacing. ▪▪ Because the bridge would be replaced, ensure the new one is also wide enough to accommodate a multiuse path or sidewalk. ▪▪ Need for additional analysis to advance the concept further.
www.gravesmillplan.com
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To turn right from a To turn right onto a freeway ramp, use the To turn left from a freeway ramp, freeway ramp from the right-turn lane like at a follow lane markings and traffic signals arterial, use the right-turn To turn right diamond from a conventional to stay on the left side of the arterial, To turn onto a lane like right at a conventional freeway ramp, use the To turn from freeway ramp, interchange and thenleft cross to athe right side after freeway ramp from the diamond interchange right-turn lane like at a follow lane markings and traffic signals passing through the interchange arterial, use the right-turn conventional diamond to stay on the left side of the arterial, Note: For simplicity, only two directions traffic lane like at a conventional Note: For simplicity, only two directions ofthen traffic areto shown. Opposing traffic follows similar routes.interchange Diagram not toofscale. and cross the right side after are shown. Opposing traffic follows similar routes. NOT TO SCALE diamond interchange passing through the interchange
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www.virginiadot.org/innovativeintersections to learn more. Visit NOT TO SCALE
Visit www.virginiadot.org/innovativeintersections to learn more.
Note: For simplicity, only two directions of traffic are shown. Opposing traffic follows similar routes.
