Project Overview

The Idaho Transportation Department is designing improvements to Interstate 84 between Caldwell and Nampa. This project is necessary to improve safety and mobility on I-84 in Canyon County. The existing interstate can no longer accommodate current traffic volumes at peak periods of the day. As the Treasure Valley continues to grow, congestion in this corridor will increase.

The planned improvements include:

• Widening I-84 to three lanes in each direction from the Franklin Road Interchange in the City of Caldwell to the Karcher Road Interchange in the City of Nampa.
• Replacement and widening of six canal and lateral crossings.
• Replacement of the Middleton and Ustick overpasses.
• Two new noise walls along I-84 near Ustick Overpass and on the Franklin Road westbound on-ramp.
• Replacement of the I-84 bridges over Linden Road.

Environmental Study

In addition, ITD completed an environmental evaluation to help determine the needed improvements that will benefit  long-term safety and capacity on the corridor while minimizing impacts to the environment and adjacent properties

The environmental evaluation included field work, analysis, surveying and mapping, environmental research and reports, geological reconnaissance and materials report, preliminary hydraulic assessments, roadway drainage analysis and public involvement.

Visit the environmental website for I-84 Caldwell to Karcher here.