This piece represents the opinion of Zillow Group Chief Analytics Officer and Chief Economist Dr. Stan Humphries.

At Zillow, we know that investing in transit today means making a down payment on housing affordability tomorrow. Vibrant regions with abundant jobs like ours must figure out how to either facilitate the construction of affordable housing near those jobs or how to transport the workers from where housing does exist to where the jobs are. Realistically, smart and equitable growth requires both. While we often focus on trying to create housing where the jobs are, this strategy brings us a trickle of affordable units when we need a flood. We love the idea of economically diverse neighborhoods with abundant affordable housing, but in practice, we seldom get both. As a result, we condemn more and more of our neighbors to either unaffordable housing or expensive commutes from more affordable areas. With ST3, we can grow into a future where families across the region from Bothell to Burien, Renton to Redmond, and from Fremont to Fife have equal access to all the opportunities for work, education, and leisure our dynamic region provides.

More than just connecting cheaper housing to opportunity, transit-oriented development in Seattle can help manage housing costs – something desperately needed amidst the current crisis in affordable rental housing. Relying on cars is expensive for residents, and building to accommodate cars is more expensive. Regulations like parking requirements play a significant role in our rental affordability crisis by passing costs onto residents or stopping new developments before they start. King County estimates that each parking spot required by building regulations adds between $20,000 to $40,000 to overall development costs. Perversely enough, this requirement results in 40% too much parking capacity in multifamily developments. Seattle city code cuts the minimum parking requirement in half for buildings within a quarter mile of frequent transit service. So more transit-oriented development can directly contribute to housing affordability of new homes without waiting on additional legislation.

Managing a vibrant and evolving region means keeping a lot of balls in the air to stay ahead of the competition. Cities like Los Angeles and Miami are cautionary reminders of growing regions that clearly delayed a lot of important decisions around transportation, helping to create their current log jam. During Zillow’s road trip to Miami last year, I was struck by how much the lack of progress on transportation issues in that metro had cascaded into an inability to make progress in other areas. Want to renovate blighted areas by creating abundant affordable housing? Surrounding neighborhoods don’t love that idea because, instead of affordable housing, they see more traffic spilling into their already over-crowded surface streets. Many neighborhoods don’t have the road capacity required for more cars, nor the public transit to absorb that burden. All conversations quickly come back to fears and frustrations around traffic and congestion.

Many opponents look at the price tag of ST3 and argue that before we fix transportation, we need to fix education. I agree that we need to fix education. But, I’d also point out that we’ve been at the effort for many decades, depending on how you define it. Putting transportation in a giant queue behind “fixing” education feels like putting it just ahead of “world peace.” I’ll be happy when all three items are ticked off our list, but waiting on one for the others seems a false choice.

Skeptics also argue that innovations like driverless cars will soon make bus and rail obsolete. I understand the logic here as I think driverless cars are rapidly approaching and will disrupt a lot about transportation, housing and the workforce. However, I don’t believe driverless cars are a panacea solution for every commute, nor are they incompatible with permanent rail. Because rail will give us the skeletal structure for moving masses to major peripheries of Everett, Tacoma, West Seattle, and the Eastside, future technologies can improve the way we move around within the gaps, solving the nettlesome first-mile/last-mile dilemma hindering current mass transit. A recent analysis of Uber rides near light rail stations in Los Angeles showed that almost a quarter of them took place during peak commute times, suggesting that passengers might be using Uber as the connective tissue between fast light rail and their initial starting points and final destinations.

Finally, some critics are unhappy with ST3’s skew toward expensive trains over cheaper buses. Sound Transit’s focus on rail maximizes its popularity among future users, because commuters are more likely to leave their cars for rail than they are for buses. Several international and national studies confirm the bias that potential transit riders have toward rail. So it makes sense for Sound Transit to focus heavily on rail and follow constituents’ preferences.

ST3 (Sound Transit Proposition 1) is a big proposal, so I can understand some hesitation. It’s a long planning horizon, for sure, but ST3 provides a forward-thinking, high-capacity skeleton that our region and economy can grow around. Our last big step forward, ST2—which delivered a system we’re now glad to have—installed a solid backbone through our region. ST3 will build out the ribcage, and allow new technologies and new growth to fill in the rest.

It’s time for our region to invest this down payment for smart growth, and vote in favor of Sound Transit Proposition 1 on November’s ballot.