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Graves Mill EB EBR 210 22
GRAVES MILL ROAD CORRIDOR STUDY Priority III Projects: DDI at US 501 Building on Priority II Projects, these recommended improvements will be needed if a maximum buildout and growth scenario occurs along the corridor. Priority III projects should be monitored over time as conditions dictate.
Diverging Diamond Interchange (DDI) What are the benefits of a DDI?
▪ Improved safety: Reduces the number of points where vehicles may cross paths ▪ Increased efficiency: Crossovers can operate with only two traffic signal phases, which allows the interchange to handle a greater volume of traffic and operate with less delay ▪ Easier access to freeway: Design allows traffic to enter and exit the freeway without 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 interchange construction
INNOVATIVE INTERCHANGES
Navigating a Diverging Diamond Interchange (DDI)
INNOVATIVE INTERCHANGES Ǧ Depending on their level of comfort, Navigating a Diverging Diamond Interchange (DDI) cyclists may navigate the intersection using vehicle or pedestrian paths h To turn left onto a freeway ramp from the arterial, follow lane markings and traffic signals to cross to the left side of the arterial, and then turn left onto the ramp
gTo turn right onto a freeway ramp from the Ǧ Depending on their level of comfort, cyclists may navigate the intersection arterial, use the right-turn using vehicle or pedestrian paths h To turn left onto a freeway lane like at a conventional ramp from the arterial, follow lane markings and diamond interchange traffic signals to cross to the left side of the arterial, and then turn left onto the ramp NOT TO SCALE h To turn left from a freeway ramp, g To turn right from a freeway ramp, use the follow lane markings and traffic signals right-turn lane like at a to stay on the left side of the arterial, conventional diamond and then cross to the right side after interchange passing through the interchange
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.
gTo turn right onto a freeway ramp from the arterial, use the right-turn lane like at a conventional diamond interchange NOT TO SCALE
hTo turn left from a freeway ramp, g To turn right from a freeway ramp, use the follow lane markings and traffic signals right-turn lane like at a g To turn right onto a freeway ramp from the to stay on the left side of the arterial, and then cross to the right side after conventional diamond interchange arterial, use the right-turn passing through the interchange lane like at a conventional Note: For simplicity, only two directions of traffic diamond interchange are shown. Opposing traffic follows similar routes.
hTo turn left from a freeway ramp, g To turn right from a freeway ramp, use the follow lane markings and traffic signals right-turn lane like at a to stay on the left side of the arterial, conventional diamond interchange and then cross to the right side after Note: For simplicity, only two directions of traffic are shown. Opposing traffic follows similar routes. Diagram not to scale. passing through the interchange Visit www.virginiadot.org/innovativeintersections to learn more.
NOT TO SCALE
