After the results of the November election were tallied, Proposition 479 passed with nearly 60% of voters in favor of the measure. Because of its passage, Prop 479 will continue the dedicated half-cent sales tax for transportation that first passed in 1985 for another 20 years — funds that have been instrumental in constructing the Valley’s freeway infrastructure.


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“This is a signature moment for the region. For 40 years, and with the unanimous support of local governments with diverse populations and needs, Valley residents have confirmed their commitment to preserving our transportation infrastructure and investing in our future mobility. Proposition 479 is not just a win for the people of Maricopa County, but a competitive edge for Arizona business,” says Maricopa Association of Governments (MAG) Chair and Chandler Mayor Kevin Hartke in a press release. “The investments will fund a transportation system to help create more than $30 billion in net new income for the region.” 

According to MAG, Prop 479 is projected to raise nearly $15 billion in revenue over its 20-year lifespan, and when combined with other state and federal funds, will support a $28 billion transportation program. Some of the projects in the plan include the construction of State Route 30 in the Southwest Valley, the completion of State Route 24 in Southeast Mesa, and improvements to both I-10 and I-17. Beyond building and expanding the Valley’s freeway system, funds from Proposition 479 will also be used to maintain road quality, invest in new arterial street safety projects and expand regional transit services.  

“Winning a ballot initiative with close to 60% support — especially when it had been mislabeled as a tax increase — is a big deal,” explains Danny Seiden, president and CEO of the Arizona Chamber of Commerce & Industry. “People in this state want the government to do its job. Building roads and filling potholes are some of the most basic things folks think the government should be doing. For being such a huge city, we average a 30-minute commute, and that’s because of our good roads.” 

Seiden adds that without the passage of Proposition 479, the growth and maintenance of the Valley’s freeway infrastructure would’ve halted until a new funding source could be implemented.  

“A new tax would’ve been required if this funding mechanism did not continue,” he notes. “All the expansion and huge announcements we’ve been seeing would be at risk, because no company wants to invest billions of dollars if it’s going to be stranded out on an island. I don’t want to sound overly dramatic, but the growth of our region was at stake with this vote, and to get to 60% [of the vote] on something that can be as boring as a regional transportation fund is exciting.”  

Economic development impact of Prop 479

Having efficient and well-maintained roads not only benefits the quality of life for Greater Phoenix residents but is also an asset for business attraction to the state.  

“Economic development is not possible without transportation and connectivity,” says Jaye O’Donnell, economic development director for the City of Mesa. “We need a robust transportation system, and the passage of Proposition 479 is instrumental for additional development opportunities throughout Greater Phoenix, but especially in Mesa.” 

Without an efficient transportation network in place, it becomes much harder to convince major companies to choose to locate in the Valley, Seiden adds. He points to the growth happening in the West Valley along the Loop 303 — something Seiden believes wouldn’t have been possible without the funds raised from Proposition 479’s predecessors, Proposition 300 and Proposition 400.  

“We hear [about how good the Valley’s freeway system is] all the time from companies, especially those coming from California. The ability to get from one side of the county to the other easily is huge, and I do think it factors into their decision to locate here,” Seiden continues. “I’ll be specific. I know when Waymo, Uber and others were doing autonomous vehicle testing, they said the chief reason they started so heavily in Arizona, besides having a governor who was very big on innovation which has continued under Gov. Hobbs, is our road quality. Now we’re a mecca for autonomous vehicles.”  

TSMC’s $65 billion investment — the largest foreign direct investment in U.S. history — was also made possible in part because of the access provided by the Loop 303. The company has attracted other businesses within its supply chain, bolstering the state’s growing semiconductor cluster. 

“It really matters how you connect that ecosystem,” Seiden concludes. “The way you can build out a true supply chain inside of a state is by having good freeways, roads and critical infrastructure. That’s a big reason why the business community was so heavily invested in Proposition 479. Having reduced commute times also helps with our air quality, so these networks are not just great for the health of the economy, but also the health of workers.”