14.10.5 Auxiliary Lanes

Auxiliary lanes can aid weaving traffic at a DDI interchange, smooth traffic flow, provide added capacity, and improve overall safety.
Figure 14-45
through
Figure 14-48
show examples of auxiliary lanes at a DDI interchange. Chapter 7 of
NCHRP Report 959
provides additional information on auxiliary lanes.
Auxiliary Left-Turn Lane Between Crossovers (Not Preferred) ( click in image to see full-size image)
Figure 14-45: Auxiliary Left-Turn Lane Between Crossovers (Not Preferred)
Auxiliary Left-Turn Lane Developed Prior to the First Crossover ( click in image to see full-size image)
Figure 14-46: Auxiliary Left-Turn Lane Developed Prior to the First Crossover
Auxiliary Lane, Shared Left and Through, Developed Prior to the First Crossover ( click in image to see full-size image)
Figure 14-47: Auxiliary Lane, Shared Left and Through, Developed Prior to the First Crossover
Auxiliary Through Lane Developed Prior to the First Crossover ( click in image to see full-size image)
Figure 14-48: Auxiliary Through Lane Developed Prior to the First Crossover