Auxiliary lanes are used to comply with capacity demand, maintain lane balance and accommodate speed changes, weaving and maneuvering for entering and exiting traffic. They are non-through lanes used to separate entering, exiting or turning traffic from the through traffic. An auxiliary lane is also an extra lane constructed between on and off ramps that allows drivers a safe way to merge into traffic while also preventing bottlenecks caused by drivers attempting to enter or exit the freeway.

Auxiliary Lane illustration

Illustration: Auxiliary Lane


Auxiliary Lane photo

Photograph: Auxiliary Lane

A. Auxiliary Lane

B. Mainlane Through Lanes

C. Express Lane