I-39/90 Expansion Project

Illinois state line to Madison, Dane and Rock counties

Collector-Distributor Lane System

In July 2020, I-39/90 northbound traffic in Janesville began traveling on the newly expanded northbound Interstate lanes. A Collector-Distributor (C/D) lane system was constructed between the WIS 26/Milton Avenue (Exit 171 A) and US 14/Humes Road (Exit 171 B) interchanges, separating Interstate through traffic with motorists transitioning onto and off I-39/90 at these two interchanges.

Motorists on I-39/90 northbound in Janesville wishing to exit at WIS 26/Milton Avenue (Exit 171 A) or US 14/Humes Road (Exit 171 B) must enter the C/D lane system prior to the first exit. Follow the overhead signage!

Watch the navigational video to understand the C/D lane system configuration! Download the C/D navigation handout.


A similar C/D lane system will be constructed on I-39/90 southbound and completed in fall 2021. Upon I-39/90 expansion completion in fall 2021, four lanes will open each way on the Interstate through the Janesville area, between WIS 26/Milton Avenue and WIS 11/Avalon Road (Exit 177).