US 60/Loop 303 Traffic Interchange Improvements

Overview

The Arizona Department of Transportation completed a feasibility study in 2022 to assess the US 60 and Loop 303 (Estrella Freeway) interchange and other intersections along US 60 from 163rd Avenue in Surprise to RH Johnson Boulevard in Sun City West.  

The study evaluated several near-term and long-term projects to improve traffic flow and developed conceptual design plans and cost estimates for each improvement.

Near-term improvements refer to smaller projects that would mitigate some traffic congestion and could be implemented sooner than the long-term improvements.

Project Area Map

Phase two US 60/Loop 303 and US 60/163rd Avenue Near-Term Improvements

In October 2024, the Maricopa Association of Governments approved new funding to implement additional US 60 (Grand Avenue)/Loop 303 and US 60/163rd Avenue near-term improvements. ADOT is currently designing these improvements with construction anticipated to begin in fall 2025 and take approximately six months to complete.

These improvements include:

US 60/Loop 303

• Widening eastbound US 60 approaching southbound Loop 303 to add an additional right turn lane.

• Widening southbound Loop 303 to extend the merge lane onto Loop 303. 

• Widening southbound Loop 303 to the US 60 ramp to have three dedicated left turn lanes onto westbound US 60 and one right turn lane onto eastbound US 60.

US 60/163rd Avenue

• Add a dedicated eastbound right turn lane into the drive between Deer Valley Road and 163rd Avenue and an acceleration lane along US eastbound 60.

• NOTE: Following the design review process, ADOT has determined not to proceed with the addition of a fourth through lane at the intersection of 163rd Avenue and US 60/Grand Avenue, due to concerns with traffic merging from four lanes into three lanes within a short distance, which would likely result in additional congestion leaving the intersection. 

What to Expect

• Construction is anticipated to begin in fall 2025 and take approximately six months to complete.
• Work will require lane restrictions and ramp closures and is expected to occur primarily during overnight hours and weekends to minimize traffic impacts.
• ADOT will provide advance notice of restrictions and closures to email subscribers and on the project web page.

Public Input

In late December 2024 through early January 2025, ADOT invited the public to comment on the additional near-term improvements. A summary of those comments are below.

Near-Term Improvements 

In April 2023 the Arizona State Legislature approved funding to initiate final design and construction of some short-term improvements. Some of these improvements were made in December 2023. Construction of the remaining improvements began summer 2024 and were substantially completed in late-November 2024.

These improvements include:

US 60/163rd Avenue

• Adding a third left turn lane from southbound 163rd Avenue to eastbound US 60.

• Adding a second right turn lane from westbound US 60 to 163rd Avenue.
• Extending the existing east- and westbound US 60 third lane to 163rd Avenue. This will provide three through lanes in each direction from the Loop 303 interchange to just beyond 163rd Avenue.
• Adding a second northbound through lane on 163rd Avenue from south of US 60.

US 60/Loop 303

• Adding a third left turn lane and second right turn from the northbound Loop 303 off-ramp to US 60 and adding a second exit lane from northbound Loop 303 to US 60.

• Adding an additional through lane along westbound US 60 at Loop 303 to accommodate the left turning traffic from Loop 303 (approaching and departing the Loop 303 interchange ramps).  The additional lane allows for a greater volume of traffic to continue through the intersection while maximizing the green signal timing for the turning movements, ultimately avoiding a back-up along the US 60/303 mainline as cars wait for the signal. 

Other improvements included restriping, new signs, traffic-signal timing adjustments and railroad coordination.

Long-Term Improvements

The feasibility study identified some possible long-term improvements that could be implemented as part of future reconstruction of the US 60/Loop 303 interchange. This project is included in the Regional Strategic Transportation Infrastructure Investment Plan and is funded in part through Proposition 479, a dedicated half-cent sales tax for transportation approved by Maricopa County voters in 2024.

Possible improvements include:

• Construct a diamond interchange at US 60 and Loop 303.
• Construct new southbound Loop 303 off-ramp and northbound Loop 303 on-ramp over the railroad tracks.
• Grade separate eastbound US 60 through lanes between 163rd Avenue and RH Johnson Boulevard to go over Loop 303.
• Build a US 60 overpass at 163rd Avenue. Traffic on 163rd Avenue could be serviced by a ground-level Single Point Urban Interchange (SPUI) interchange.

NOTE: These improvements are subject to change. Further study will be required to determine the final configuration of the long-term improvements. According to the Maricopa Association of Government's Freeway Life Cycle Program, predesign is planned to begin in Fiscal Year 2028 and advertisement for construction is anticipated in Fiscal Year 2033.

Background/Timeline

• In June 2022 the US60/SR303L Traffic Interchange (TI) Feasibility Report (See report under the Document tab) was completed.
• In December 2023 ADOT completed the following short-term improvements:
  • Added a second right turn lane from northbound/westbound US 60 to 163rd Avenue.
  • Extended the existing westbound US 60 third lane to 163rd Avenue.
  • Restriped westbound US 60 for third lane and two right-turn lanes to 163rd Avenue.
• Construction for the other short-term improvements began in late-July 2024 and was substantially completed in late-November 2024. 
• Additional short-term improvements are planned to begin in fall 2025
• Long Term Improvements predesign is planned to begin in FY 2028 and advertisement for construction is anticipated in FY 2033.

Documents

Stay Informed

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• Phone: ADOT Project Information Line: 855.712.8530
• Email: [email protected]
• Mail: ADOT Communications, 1655 W. Jackson St., MD 126F, Phoenix, AZ 85007