The Dubuque region would see a number of interstate improvements. The map below shows these various improvements. Dotted blue lines indicate optional alignments and corridors.

Ultimate Interstate 558 - Dubuque West End spur
Description Ultimate interstate 558 would run cosigned along US-20 from where it would separate from planned ultimate interstate 88 west of Dubuque to the railroad overhead near the Kennedy Mall and shopping centers. The route could be eventually extended further east using a compact freeway alignment with one way frontage roads and slip ramps. ultimately the freeway extension could connect to the existing expressway already built, which would need some modifications to bring up to interstate standards.
Purpose and Need Provides a freeway link to north I-25 and Santa Fe bypassing Albuquerque.