Interstate 17 (I-17): Phoenix to Flagstaff Route, Climb and Crash Record

How long is I-17?

FHWA's Route Log puts I-17 at 145.95 miles as of January 2026, every one of them in Arizona. Wikipedia lists 145.93 miles, and Interstate Guide prints 145.76 from the January 2022 edition of the Route Log, so the three figures sit within a fifth of a mile of each other.

I-17 shares no pavement with another Interstate, so the crash rate below uses the same 145.95 miles. US 60 is signed along with it from Thomas Road (exit 201) to the southern end. Exit numbers start at 194 instead of 0 because I-17 kept the milepost numbering of State Route 69.

Where I-17 starts and ends

The southern end is a junction with I-10 in Phoenix, where the Maricopa Freeway continues east as I-10 and US 60. The northern end is exit 340 in Flagstaff, at I-40, and the road carries on into town as State Route 89A, better known there as Milton Road.

Going north, the freeway leaves the Phoenix suburbs at Anthem and New River and passes Black Canyon City, the Sunset Point rest area at exit 252 and Cordes Lakes. It then serves Camp Verde (exit 287) and Montezuma Castle National Monument (exit 289), crosses the Verde River on the Dan Bell Memorial Bridge, and reaches the State Route 179 turnoff for Sedona at exit 298. Munds Park and Kachina Village come last before Flagstaff. Phoenix sits at 1,117 feet and Flagstaff at about 7,000.

Most of the road is named the Arizona Veterans Highway. In metro Phoenix most of it is the Black Canyon Freeway, and the southernmost 4.16 miles, from the Durango Curve to I-10, belong to the Maricopa Freeway.

Interstate junctions along I-17

The list has two entries, in order from south to north: I-10 in Phoenix and I-40 in Flagstaff. I-17 actually meets I-10 twice, once at the Stack (I-17 exit 200A), 6.49 miles from the southern end, and again where I-17 ends past the Durango Curve. Loop 101 (exit 214C) and Loop 303 (exit 221) are Arizona state freeways, so they are not listed.

Fatal crashes on I-17

Fatal crashes on I-17 numbered 117 from 2020 to 2024, and they killed 131 people, about 26 a year. Spread over 145.95 miles, that is 18.0 deaths per 100 route miles a year, close to double the Interstate network average of 9.5. Among the 56 routes long enough to rank, only I-45, I-4 and I-30 had higher rates.

The whole route is in Arizona, so the state figure and the route figure are the same. Maricopa County, home to Phoenix, had 81 of the deaths, more than three in five. Yavapai County, in the middle of the route, had 34, and Coconino County, which takes in Flagstaff, had 16.

The yearly count climbed from 22 in 2020 to 24 in 2021, 26 in 2022 and 31 in 2023, the worst of the five years. It eased to 28 in 2024.

Counties with the most I-17 crash deaths

Bridges on I-17

Bridges carrying the I-17 main line number 121 in the 2025 National Bridge Inventory, and none of them rates Poor: 62 rate Good and 59 rate Fair. Half were built in 1967 or earlier.

Between Anthem Way and Sunset Point, ADOT's I-17 Improvement Project widened 10 bridges and replaced two. That work ran from September 2022 to December 2025.

Tolls on I-17

No toll facilities appear on I-17 in FHWA's January 2023 toll inventory, and a trip from Phoenix to Flagstaff costs nothing in tolls.

ADOT finished two reversible flex lanes between Black Canyon City and Sunset Point in December 2025, after that inventory was compiled. They usually carry northbound traffic Monday through Saturday and switch to southbound on Sunday, and ADOT's project page describes them without mentioning a toll.

From stagecoach trail to Black Canyon Freeway

A stagecoach road through Black Canyon ran between Cañon, now Black Canyon City, and Prescott in 1878, roughly along the line I-17 follows today. Arizona created State Route 69 from Phoenix to Prescott in 1936 and State Route 79 north toward Flagstaff in 1954. The Black Canyon Highway from Phoenix to Flagstaff was finished in May 1956, short of Interstate standards, and later that year it was folded into the new Interstate system, then received the I-17 number in the August 1957 numbering plan.

Interstate Guide says the Black Canyon Freeway in Phoenix opened in pieces from 1958 to 1965, starting at Grand Avenue and Thomas Road, while Wikipedia dates the first freeway interchange west of downtown to 1950. The last section opened in 1978; Wikipedia places it near Camp Verde and Montezuma Castle, while Interstate Guide puts it near Dugas Road.

The Phoenix freeway was designed for 20,000 vehicles a day and carried up to 220,000 by 2003. A 7-mile design-build widening from Thomas Road to Peoria Avenue wrapped up in September 2000 for $82 million, and the North Stack with Loop 101 was completed on November 1, 2000, at a cost of $63.7 million. A rebuild of the old cloverleaf where I-17 meets I-40 in Flagstaff was completed in September 2002.

The most recent big job covered 23 miles from Anthem Way to Sunset Point. ADOT added a third lane in each direction for the 15 miles to Black Canyon City and built the flex lanes, the first in Arizona, on the 8 miles beyond it. The state delivered it as a public-private partnership under a design-build-operate-maintain contract.

I-17 traffic and road conditions

Because I-17 never leaves Arizona, one traveler site from ADOT covers every mile of it, from the Phoenix interchanges to the Flagstaff end. Use the link below for current closures and incidents.

I-17 questions