Overview
The Arizona Department of Transportation, in partnership with the Gila River Indian Community and Maricopa Association of Governments, is proposing to construct improvements along SR 347, between Interstate 10 (I-10) and the northern limits of the city of Maricopa.
Project Elements
The project team will evaluate:
- Widening SR 347 by one lane in each direction, primarily toward the median (or outside – where required) from the city of Maricopa Limits (MP 175.7) to I-10 (MP 189.1).
- Widening existing bridges at Santa Rosa Wash, Santa Cruz Wash and Gila River.
- Extending box/pipe culverts as needed.
- Intersection improvements at Casa Blanca Road, Borgia Road (Sacate Road), Mammoth Way (Cement Plant Access Road) and Old Maricopa Road to accommodate a six lane highway.
- Casa Blanca Road and Mammoth Way Intersections: Additional modifications to improve traffic flow and safety are planned at these two intersections. (These improvements will take place on a different timeline than the other project elements.)
Project Area
Alternatives Being Considered
The project team has developed two alternative design concepts for the Casa Blanca Road/SR 347 intersection to make improvements for traffic flow and safety.
Casa Blanca Road Intersection Alternative 1 - Florida T
The Casa Blanca Road Alternative 1, commonly referred to as a ‘Florida T,’ would make the following improvements to the existing “Standard T” signalized intersection:
- Left-turning traffic from Casa Blanca Road onto SR 347 will enter a new acceleration lane to get up to speed before merging into SR 347 traffic. A four-foot buffer area between the acceleration lane and existing lanes on SR 347 would be included to provide additional space between the SR 347 traffic lanes.
- Southbound traffic on SR 347 will be free-flowing and not have to stop for the traffic entering from Casa Blanca Road.
- The southbound SR 347 left turn lane onto Casa Blanca Road and the northbound SR 347 right turn lane at Casa Blanca Road will be lengthened to allow more vehicles to wait to turn and reduce back-ups for through-traffic.
- Casa Blanca traffic turning right onto northbound SR 347 will also be able to turn freely without having to stop at the signal, with the addition of a dedicated right-turn lane and an extended acceleration lane to merge into northbound SR 347 traffic.
Casa Blanca Road Intersection Alternative 2 - Improved Standard T
The Casa Blanca Road Alternative 2, or an Improved Standard T, would make the following improvements to the existing standard ‘T’ signalized intersection:
- The southbound SR 347 left turn lane to Casa Blanca Road will be lengthened to allow for more vehicles to wait to turn, reducing back-ups for through- traffic.
- The northbound SR 347 right turn lane to eastbound to Casa Blanca Road will also be extended.
- Casa Blanca Road traffic turning right onto northbound SR 347 will also be able to turn freely without having to stop at the signal, with the addition of a dedicated right-turn lane, and an extended acceleration lane to merge into northbound SR 347 traffic.
Mammoth Way Intersection – Proposed Improvements
The proposed improvements proposed at the Mammoth Way intersection would make the following improvements to the existing standard ‘T’ signalized intersection:
- The southbound SR 347 left turn lane and the northbound right turn lane to Mammoth Way will be lengthened to allow for more vehicles to wait to turn, reducing back-ups for through-traffic.
- The eastbound left turn lane into the cement plant will also be lengthened.
- Traffic turning right from Mammoth Way onto northbound SR 347 will be able to turn freely without having to stop at the signal, with the addition of a dedicated right-turn lane, and an extended acceleration lane to merge into traffic.
Borgia Road Proposed Improvements
Proposed improvements to the non-signalized intersection at Borgia Road would include:
- Adding an extended eastbound right turn lane from SR 347 to Borgia Road.
- Adding a dedicated right-turn lane from Borgia Road to northbound SR 347. Traffic turning right onto northbound SR 347 would be able to turn freely without having to stop with the new lane and the addition of an acceleration lane to merge into traffic.
Maricopa Road Intersection - Proposed Improvements
Proposed improvements to the existing ‘Florida T’ signalized intersection at Maricopa Road include:
- Lengthening the acceleration lane for traffic turning south to SR 347 from Maricopa Road.
- Maricopa Road traffic will be able to turn right freely onto SR 347 without stopping at the signal.
- A second left turn lane to northbound Maricopa Road will be added on SR 347 to allow for more vehicles to wait at the signal and reduce back-ups at the intersection.
- The right turn lane on Maricopa Road will also be lengthened to decrease congestion at the intersection.
Proposed Improvements to widen the SR 347 Corridor, between I-10 and the city of Maricopa
The project team is evaluating options to widen SR 347 by one lane in each direction within the median from the city of Maricopa to just north of Riggs Road. The north section of the corridor, roughly between Maricopa Road and I-10, is being evaluated for widening both in the median and to the outside. With the additional lanes, the project would widen the existing bridges at Santa Rosa Wash, Santa Cruz Wash and Gila River. Intersection improvements will also be evaluated to accommodate a six lane highway.
Aug. 15 In-Person Public Meeting
The Arizona Department of Transportation and its project partners held an in-person meeting on proposed improvements to the SR 347 corridor, between I-10 and the city of Maricopa, on Thursday, Aug. 15. The project team shared project details and were on hand to discuss the proposed improvements for the SR 347 corridor widening, as well as the Riggs Road traffic interchange, and answer questions.
Documents
Public Meeting Presentation (English)
Public Meeting Script (English)
Public Meeting Display Boards (English)
Public Meeting Presentation (Spanish)
Public Meeting Script (Spanish)
Public Meeting Display Boards (Spanish)
Project Videos
Casa Blanca Road and Mammoth Way Visual Simulation Videos
Design Schedule
The corridor widening is currently in design and is expected to take two years to complete. It is not currently funded for construction. If funding is available, it will be ready to go to construction at the end of 2025.
The intersection improvement project for the Casa Blanca Road and Mammoth Way (Cement Plant Access Road) intersections is funded for construction. Design is underway and it is anticipated to advertise for construction in summer 2025.
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ADOT welcomes your questions and comments. Please contact us in any of these ways:
- Phone: ADOT Project Information Line: 855.712.8530
- Email: [email protected]
- Mail: ADOT Communications, 1655 W. Jackson St., MD 126F, Phoenix, AZ 85007
