State Route 30 , 347 and 366 in Arizona

State Route 366 in Arizona

State Route 30 in Arizona

Get started good year
End Phoenix
Length 15 mi
Length 24 km

State Route 30 is a planned freeway and state route in the U.S. state of Arizona. State Route 30 is planned as an east-west route in the west of the Phoenix metropolitan area, parallel to Interstate 10 between Goodyear and Phoenix with a planned length of 15 miles in the first phase.

Travel directions

The preferred alternative for 2019 will have State Route 30 initially starting at Sarival Avenue, just south of Maricopa County Highway 85. The highway then heads east, south of the suburbs of Goodyear, Avondale, and Tolleson. State Route 30 runs through flat terrain, on the edge of suburbanization, parallel to the Salt River. The planned route ends near the junction of Loop 202 and Broadway Road.

  • ANSWERMBA: Provides information about Arizona history.


Beginning in the mid-2000s, plans were made to improve traffic conditions in rapidly growing west Phoenix. These improvements were initially made to Interstate 10, later a parallel highway was planned to relieve I-10, this was initially planned as State Route 801. At the time, it was planned to open the highway in the 2021-2025 period. but the post-2008 recession slowed the plans.

The planning of State Route 30 continued, in 2016 it was considered to build the road as a toll road. In the period 2017-2019, four alternatives were filtered out into a preferred alternative, which led to a preferred alternative, an Environmental Assessment and a FONSI on December 16, 2019.

The name of the planned highway was established in 2017 as the Tres Rios Freeway, named after the three rivers Gila, Agua Fria and Salt.


Phase 1 will include a motorway on a greenfield section for 15 miles between Goodyear and Loop 202. This section will be constructed in 2×3 lanes, with space reserved for 2×5 lanes. In the future, the highway may be extended further west to a similarly extended Loop 303, which forms Phoenix’s westernmost beltway. When determining the preferred alternative in 2019, the construction of the motorway was mentioned from mid-2026.

State Route 347 in Arizona

Get started Stanfield
End Sun Lakes
Length 29 mi
Length 46 km

State Route 347 is a state route in the U.S. state of Arizona. The road forms a north-south route in the center of the state, from near Stanfield to near Sun Lakes, just south of the Phoenix metropolitan area. State Route 347 is 46 kilometers long.

Travel directions

The road begins west of the village of Stanfield at an intersection with State Route 84 and heads north through an area of ​​irrigated agriculture to Maricopa, the only town on the route. The road forms Maricopa ‘s main street and crosses State Route 238. North of Maricopa the road leads through the desert and is a 2×2 divided highway. The road ends at a junction with Interstate 10, on the edge of the Phoenix metropolitan area.


Maricopa was always a small hamlet, but it does have a station where through trains stop. The road from Maricopa to the north was built in the late 1930s and ran until the then US 80 in Tempe. In the 1950s, the road was built south from Maricopa to SR-84. However, it was not until 1997 that State Route 347 was assigned to the road.

The road passed through almost uninhabited area, with only some houses around Maricopa station and agriculture south of Maricopa. The town of Maricopa grew extremely fast after 2000, from 1,000 inhabitants to more than 43,000 inhabitants in 2010. State Route 347 is the main connection from Maricopa to the main road network, especially towards Phoenix. That is why State Route 347 had to be widened in a hurry to a 2×2 divided highway between Maricopa and the I-10. This happened in or before 1996.

In 2019, the level crossing in Maricopa was replaced by a viaduct with 2×2 lanes. The official opening followed on July 13, 2019, although the project was not ready until the end of that year.

Traffic intensities

Every day, 3,200 to 5,600 vehicles run between SR-84 and Maricopa, rising rapidly to 42,000 vehicles in Maricopa and 27,000 to 31,000 vehicles between Maricopa and I-10.

State Route 366 in Arizona

Get started Mount Graham
End Swift Trail Junction
Length 28 mi
Length 46 km
Mount GrahamSwift Trail Junction

State Route 366 is a state route in the U.S. state of Arizona. The road connects the summit of Mount Graham (3,269 m) with US 191 at Swift Trail Junction. The road is 46 kilometers long.

Travel directions

The State Route 366.

State Route 366 begins south of Safford at an intersection with US 191 at 1,000 feet. From here the road rises for more than 2 kilometers, through a series of hairpin bends. The base of the mountain is desert, but higher up is dense forest. The last 13 kilometers of the road is a gravel road, elsewhere the road is quite wide with two marked lanes. There are hairpin bends. The asphalted part ends at an altitude of 2,800 meters. The Mount Graham International Observatory can be reached via the maintained gravel road and is located at an altitude of approximately 3,180 meters. The top of Mount Graham can only be reached by tracks.


State Route 366 was created in 1960 and originally ran only from US 191 to the base of Mount Graham, but was extended to a ranger station the same year. This was a gravel road at the time. About two-thirds of the route has since been paved. In 1989, construction began on the Mount Graham International Observatory, an astronomical observatory near the top of Mount Graham.


The road is in principle accessible all year round, but in winter the driving conditions are often very poor and the road is periodically closed. The Arizona Department of Transportation maintains the tarmac portion, the observatory the last eight miles of gravel road. In winter, the observatory is only accessible with four-wheel drives and snow chains.

Traffic intensities

Every day 800 vehicles drive on the flat part and 150 vehicles until the end of the asphalt part at the ranger station. The rest is not controlled by the Arizona Department of Transportation.

State Route 366 in Arizona