What is happening at the Mill Avenue Underpass?  

Artist Joe O’Connell and Creative Machines created artworks that add color and vibrancy to this site. Construction of the first phase is complete at the Mill Avenue underpass as Tempe prepares for the installation of the second phase of “Sun Garden,” a vibrant public art project. 

 

Phase one included structural repairs to the underpass retaining walls and the addition of 15 new nature-inspired sculptures designed by Arizona-based artist team, Joseph O’Connell and Creative Machines, Inc. The translucent, colored elements cast shifting shadows throughout the day. The sculptural artworks were installed in the summer of 2025.

Phase 2 will focus on lighting and landscaping. City of Tempe and partners are working on installing the required power during January and February of 2026. Landscape enhancements will be installed in early February.  When this Phase is complete, the underpass will be a colorful, welcoming landmark for all to enjoy – day and night.

Why is this art piece being installed? 

This project is part of the City’s Refresh Tempe initiative to enhance public spaces and reflects the community’s input and creative spirit.

Over the last several years, the Tempe City Council has been increasing reinvestments in parks, streets, public art and more. This Refresh Tempe initiative aims to add and maintain Tempe amenities and infrastructure in order to improve quality of life for all community members. The project also aligns with the Tempe Arts + Culture Plan, which calls for signature works of public art.

Click here to learn more about the Refresh Tempe initiative
Click here to learn more about Tempe Arts & Culture

This regionally distinctive project will bring the highly trafficked underpass to life in a dramatic way. For many travelers, this stretch of road serves as a gateway to Downtown Tempe and Arizona State University. Approximately 18,000 vehicles travel the underpass daily in addition to the pedestrian and bike traffic in this corridor, which encompasses Tempe High School and Tempe St. Luke’s Hospital.

How was the art selected? 

A national artist competition was held to select the artist for this significant installation. Arizona-based artist Joseph O’Connell + Creative Machines, Inc. was chosen to design the project, and fabrication is currently underway. Tempe Public Art hosted several public meetings with the surrounding neighborhood and Tempe High School to gather input about the design.

Will supportive landscaping be added to the installment?  

Yes, the space is designed to be fully enhanced with complementary landscaping that beautifies and completes the overall installment. Landscaping will be contingent upon city infrastructure schedules and are expected to be addressed in winter 2026. 

Will the art piece have lighting at night? 

Yes, the piece will be vibrant and highly visible at night once power and infrastructure and power are activated; installation is anticipated to be complete in early 2026.