Interstate 10 in Arizona - History

History

Interstate 10 in Arizona was laid out by the Arizona Highway Department in 1956-58 roughly paralleling several historic routes across the state. Particularly east of Eloy, it follows the Butterfield Stage and Pony Express routes, and loops south to avoid the north–south Basin and Range mountains prevalent in the state. In fact, the route from its junction with Interstate 8 east to New Mexico is almost exactly the same route used by the old horse-drawn stagecoaches, which had to go from waterhole to waterhole and avoid the hostile Apache Indians. This is why I-10 is more of a north–south route between Phoenix and Tucson than east–west. The Southern Pacific Sunset Route line had to take the route of least hills, and in the 1920s highways were laid down next to the trains across southern Arizona.

When the project was being designed in the 1950s, the Arizona Highway Department fought for a nearly straight-shot west from Phoenix for the new freeway, instead of angling northwest out of Phoenix along U.S. 60-70-89, through Wickenburg. Wickenburgers battled to bring the freeway through their city but lost that battle. The detour up through Wickenburg was logical decades earlier, when nearly all U.S. highways through Arizona were laid out along railroad tracks, and U.S. 60-70 was routed mostly parallel to the Santa Fe rail tracks east of Wickenburg, and the Arizona and California Railway west to Vicksburg. The two old federal routes then struck west across the desert and state line, picking up the Southern Pacific mainline at Indio, California, and I-10 overlies the old roads most of that distance.

Moving east from the California line at Ehrenburg, I-10 follows the old route of U.S. 60-70 for the first 31 miles (50 km) east from Blythe, California. In 1960, this western-most stretch of I-10 was built from near the Colorado River east to the future spot where the "Brenda Cutoff" section of I-10 would connect a decade later. Until the early 1970s, this was the last freeway stretch until Phoenix. The "Brenda Cutoff" was named for a gas station on the old road just east of the fork where U.S. 60 now terminates at I-10. Now an obscure name, "Brenda Cutoff" was the working title that the Arizona Highway Department called the stretch of freeway from U.S. 60 to near Buckeye. The Brenda Cutoff paralleled old sand roads used in the 1920s for Phoenix-L.A. traffic, but mostly abandoned after U.S. 60-70 was built to the north, through Wickenburg.

The Brenda Cutoff's opening on June 18, 1973 was eagerly awaited and was a big deal in newspapers in Phoenix and Los Angeles. It saved motorists from having to drive through Glendale, Sun City, Wickenburg and Salome, 20 miles (32 km) out of the way, and it eliminated about 80 miles (130 km) of two-lane highway. But the freeway was opened only as far east as Tonopah, and heavy traffic was routed down narrow county roads through the desert and fields between Tonopah and Buckeye. In addition, there was only one very-small gas station on the very-long route between Buckeye and Quartzsite, on the old county road at the tiny crossroads of Palo Verde. Signs warning "NO SERVICES NEXT 106 MILES" were posted at either end of the Brenda Cutoff those first few years.

The freeway was extended past Tonopah as far east as Phoenix's western fringes in about 1974. I-10's freeway section ended in Goodyear until the controversial Papago Freeway was finished across the western Valley of the Sun in 1990. During the "west valley gap" years, westbound I-10 traffic was routed off the Maricopa Freeway at 19th Avenue in Phoenix, and stayed on the access road as it curved past the Durango Curve. Los Angeles-bound traffic then turned left on Buckeye Road and followed the "TO 10" signs down Buckeye Road (first marked U.S. Route 80 until 1977, then Arizona 85) for nearly 15 years.

The interstate's route through Phoenix was hotly contested in the 1960s, 1970s and early 1980s. A plan proposed by the Arizona Department of Transportation involved monstrous block-sized 270-degree "helicoil" interchanges at Third Avenue and Third Street that would connect motorists to freeway lanes 100 feet (30 m) in the air, but voters killed it in 1973 as a result of opposition from the Arizona Republic newspaper and a growing nationwide anti-freeway sentiment. Voters on election day were treated to a photo depiction on the front page of the newspaper that in later years was shown to have drastically-overstated the freeway's height, but there is no question the proposed viaducts and helicoils would have been a visual gash across central Phoenix.

Beginning in 1961, a stub of what is now the route of Interstate 10 was built northward from the Maricopa Freeway (then Interstate 10) along 20th Street, ending 1/2 mile north at Buckeye Road. The I-10/I-410 interchange was the first multi-level interchange in Arizona and lasted until the Papago Loop was built as a real freeway in the 1980s. It was first posted as Interstate 410, then as Interstate 510. This putative freeway was two lanes in each direction and would have been hopelessly inadequate as a leg of the "Inner Loop" as it was intended. The spirit of Interstate 510 lives on as "Arizona 51," the section of freeway paralleling 20th Street north of the "Mini Stack" interchange with Interstate 10 and Loop 202.

After 1973, Arizona engineers favored a more-modest plan to link I-10 with Interstate 17 at the "Durango Curve" near 19th Avenue at Buckeye Road, and avoid the "Moreland Corridor" Papago Freeway alignment by adopting a route south of Buckeye road. In 1983, ADOT unveiled the current below grade plans on Moreland Street, three blocks south of McDowell Road. Despite some local opposition, I-10 was finally completed in central Phoenix on the Papago Freeway alignment, 3/4 of a mile north of Van Buren Street, on August 10, 1990. The state is now considering a reliever west valley freeway, parallel to I-10 on the old Durango Street corridor, and was originally designated as Route 801, which has since been changed to Arizona State Route 30.

The original 1962 alignment of I-10 through Phoenix was on the Black Canyon and Maricopa freeways, now signed as I-17 and U.S. 60, starting at about Grand Avenue. From 1962-74, Interstate 10 in Phoenix ended at 40th Street, and truck traffic through Phoenix and Mesa was directed to use Arizona Route T-69 via 40th Street south and Baseline Road east to connect to state Routes 87 and 93, the shortcuts to Tucson. The 10 signs were moved from the Maricopa Freeway to the Papago Freeway Inner Loop alignment when it opened in 1990 - the last gap of I-10 to be completed between Santa Monica and Jacksonville. This was the only time in Arizona where the posted freeway was moved from one road to another: the state never posted Interstate signs on older state or U.S. highways... ADOT instead made frequent use of interstate shields with the word "TO" above and arrows below the shield.

For several years in the early 1970s an orphan section of I-10 was opened between Baseline Road and Williams Field Road (now Chandler Blvd.) but was not marked as any highway, nor was it connected to the rest of the Interstate Highway System. ADOT, it seems, did not want to divert trucks down from T-69 in Guadalupe down into the cotton fields west of Chandler. This section got its interstate signs when the freeway south to Casa Grande was completed in about 1970, and the "Broadway Curve" was connected a year or so later—for almost two years, I-10 traffic used Baseline Road and 40th Street through the Japanese flower gardens until the last link between Tucson and Phoenix opened in about 1972.

From 1958-1972, the interstate was unmarked south from Tempe and Mesa, and traffic used either State Route 87 (Arizona) through Coolidge or State Route 93 (Arizona) through Casa Grande, or U.S. 80/89 through Mesa and Florence. Interstate 10 signs reappeared at the town of Picacho, the 1962-1970 western terminus of the freeway from Tucson.

The road from Casa Grande to Tucson was originally Arizona routes 84 and 93, and when it was rebuilt as a freeway in 1961-62 it was cosigned as Interstate 10 and routes 84 and 93 through 1966, when 84 was truncated at Picacho. This section of interstate was completed in 1961, and forced the demolition of the town center at Marana, which has never really recovered. The freeway through Tucson, which was rebuilt and widened in stages from 1989 to 2009, with frontage roads added, was originally signed as State Route 84 from Miracle Mile to Sixth Avenue.

The original highway from Casa Grande to Tucson entered the Old Pueblo via Miracle Mile, a road modeled after German Autobahns but without overpasses or an exclusive right of way. Traffic circles at either end of Miracle Mile were the best Tucson could come up with in 1937. The section of Miracle Mile West stretching between Miracle Mile and the Southern Pacific overpass was signed as Business Loop 10, State Route 84A and State Route 93 in the 1960s. It is now marked as the southern leg on State Route 77, the new designation for US 80-89 north out of Tucson. The Business Loop designation was dropped in 1998.

The present-day Interstate 10 alignment along the Santa Cruz River was laid out after a city bond issue passed in 1948 to build a riverbank-side boulevard with room for a four-lane freeway in the median to follow. The first section of bypass artery, from Congress Street north to Miracle Mile West, was opened in 1954 but had no overpasses or interchanges at Grant Road, Speedway Boulevard or St. Mary's Road. The freeway was finally built after the state took over the bypass and promised it interstate status in 1958, and parts of it obliterated the original road. It was first signed State Route 84.

The old cloverleaf at Sixth Avenue was the first built in Arizona, opening in the early 1950s as a southern Tucson gateway junction to the roads linking Tucson, Benson, Nogales and the hoped-for Tucson bypass along the Santa Cruz River. It was converted to a diamond interchange by 1964 and the old "quick dip" underpass was removed and replaced by an interstate-standard overpass in the late 1980s.

Although the controversial Interstate 10 route across Phoenix was the last gap of Interstate 10 to be completed, two pieces of the interstate were subsequently left sitting on divided remnants of old U.S. 80 and were neither built to interstate nor modern safety sections. One was the old Sixth Avenue interchange, and a small section of freeway east to the overpass over the old Southern Pacific (now UP) spur to Nogales and Guaymas. That section was replaced about 1990.

The last section of old U.S. 80 that carries the Interstate 10 traffic is an underpass beneath the Union Pacific mainline east of Tucson, where the freeway median shrinks to a guardrail at Marsh Station Road and the Pantano railroad overpass is too low. The Marsh Station Road interchange was replaced in 2011, with the railroad mainline rerouted in 2012. The remainder of the old U.S. 80 section will be rebuilt to current freeway standards, with the railroad overpass removed, starting in the fall of 2012.

East of Tucson, Interstate 10 parallels and in some cases overlies old U.S. 80 to Benson, and was originally co-signed as U.S. 80 and State Route 86. From Benson, the Interstate follows the Southern Pacific mainline east through Willcox and Bowie to New Mexico, rather than bend south to the Mexican border along old U.S. 80 (signed as State Route 80 after 1989), through Douglas. The road from Benson east through Willcox was designated State Route 86 in about 1935, that route number was subsequently shifted west and exists now between Why and Tucson. The bypass around Benson was opened about 1979, and other than the Phoenix gap was the last section of Interstate 10 to be opened.

The Arizona Department of Transportation in 2008 conducted a feasibility study of building new bypass freeways around Phoenix and Tucson and "straighten" Interstate 10 across the state. One route would have gone roughly from Buckeye east to Florence, then east through mountainous terrain to the Sulphur Springs Valley and connect with the existing Interstate 10 near Bowie. But this new roadway would traverse some environmentally fragile areas and was opposed as a gateway to urban sprawl. Another studied alignment would bypass Tucson to the south, forming a looping bypass freeway from Marana through the Avra Valley to Green Valley to Benson, an alternative that is still being studied.