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Autonomous vehicles could ruin our downtowns. But not if we act now

January 05, 2018

By David Dixon and Jason Schrieber

The International Downtown Association (IDA) membership is ideally positioned to prod cities to plan for autonomous mobility strategies that work

The allure of traveling without having to drive, enjoying a cocoon of digitally-connected work, leisure, socializing, or sleep, is irresistible. But consider this: The average street is a model of inefficiency. Travel lanes consume more than two-thirds of the right-of-way but can move no more than 2,000 people per lane each hour. Compare that to bike lanes (7,500 per hour), sidewalks (9,000 per hour), and transit lines (20,000 per hour.)

Yes, autonomous vehicles will make roads safer, but if planners and governments (with help from urban place-management groups) don’t focus the great efficiencies of driverless technologies on shared mobility, we will make our current dystopia—physical isolation, hours-long commutes, severe mobility, and economic stratification—exponentially worse.

The mobility revolution: History and hope

The four mobility revolutions—connected, automated, electric, and shared vehicles—date back at least to The Jetsons of 1962. Pilot versions of the idea began with the Intelligent Vehicle Highway System of 1990, and the enabling technology—smart mobile devices—landed in the hands of the public with the first iPhone in 2007. Ten years later, ubiquitous mobile data and communication have transformed how a generation of Lyft- and Uber-using Millennials travels. Today, miles traveled per capita are near historic lows and shared rides are becoming a seamless part of daily life.

In a few years, automation will come to shared-mobility vehicles. In fact, Uber (in Pittsburgh, Tempe, and Phoenix) and Lyft (in Boston) are testing this model. Dozens of other companies have pilot programs under way.

The four revolutions will arrive first in downtowns, with highly visible impacts.  That puts the International Downtown Association (IDA) membership in an ideal position to prod hesitant municipalities to plan for autonomous mobility and to convene and lead essential public conversations on what form it should take across the city. The rapid spread of ride-sharing occurred with virtually no planning. The four revolutions will arrive almost as quickly, but we can’t afford not to plan for them.

We need look no further than a previous 10-year revolution. From 1945-1955, the number of automobiles on the road grew sharply spurring  a massive restructuring of the transportation system. Here, the impact of insufficient planning had many unintended consequences. The full revolution took decades to complete, but by 1955 we had in place policies and infrastructure (parking requirements, minimum lot sizes, the interstate highway system, and more) tailored to the automobile’s unique abilities and needs. Unintended consequences included sprawl-form development, suburban isolation, disproportionate infrastructure spending, and harmful environmental impacts.

Fortunately, our earlier experience taught us invaluable lessons—about land use plans, infrastructure programs, social preferences, and environmental impacts—giving us tools to make wiser decisions when autonomy comes. However, the window of opportunity for creating sound laws, regulations, design standards, and other measures to shape autonomy is closing. We need to start this work immediately, and we need to get it right.

Our new approach must:

  1. Capitalize on the efficiencies of sharing
  2. Reflect evolving urban lifestyles
  3. Unlock investment, jobs, and fiscal benefits
  4. Make access equitable
  5. Address climate change

Each area requires us to think differently about mobility, with a focus not on what transportation technology can do but rather on how it can best support personal travel decisions. We shouldn’t ask how we’ll get to our destination but why we’re going and what’s motivating us to go.

1. Efficiencies of sharing

New-mobility planning must focus first on how cities move people and the inefficient allocation of space—2,000 people versus 20,000—that automobile accommodation has forced on streets and places.

The launch of shared autonomous vehicle (SAV) pilots by transit agencies in Tampa and Las Vegas suggests how automation can greatly increase the efficiency of downtown streets by providing reliable and frequent door-to-door “micro-transit” throughout the day, carrying 8-10 people per vehicle with dramatically reduced labor or fuel costs.

At a high end of 5,000 people per hour, SAV systems can redefine car-choked downtowns as transit-oriented development overnight. By themselves, however, they’re no panacea—their true value lies in unlocking other, more space-efficient and economical choices. By reliably stopping for pedestrians, staying out of bike lanes, and requiring no new parking, SAVs can make other urban travel modes more attractive to casual users by assuring safety and freeing up space those modes can use to improve their operating efficiency.

These same casual users have pioneered car-free urban lifestyles, spearheading major shifts toward walking, biking, and ridesharing. Biking and walking will always require less space than powered vehicles, and only a full transit vehicle can achieve better efficiencies than SAV microtransit. If cities use SAVs to create bigger, safer lanes and parking for other modes and, eventually, for automated buses, their streets can accommodate the mobility needs of many more people—residents, workers, and visitors—without increased traffic. Individual automated cars can’t deliver efficiency gains like that.

2. Evolving urban lifestyles

Common lifestyle needs of millennials and baby boomers—our most car-free demographic cohorts—is driving population growth in cities as different as Detroit and Los Angeles. Easy and efficient mobility options that connect urbanites to work, amenities, and social opportunities have pushed transit ridership up in some cities, set new records for bicycle use, and brought new parking demand to near zero in many downtown locations.

As SAVs add a vast network of new transit connections that also protects bicyclists and walkers, we can eliminate the need for privately-owned vehicles at a site level and, eventually, throughout downtown. Doing away with all parking requirements can eliminate the significant cost of car ownership for residents while boosting new development (because new projects will becomes more feasible without the cost of on-site parking).

Hyper-sharing of parking can justify existing garages for many years, but these structures will eventually warrant redevelopment to active uses as car-free living spreads among urban residents, workers, and visitors. The Future of Parking in Boston report (2016) and coordinated autonomous vehicle policies represent are both examples of how cities are beginning to think about the role of SAVs. Much work remains to be done—most cities have barely begun thinking about the topic.

3. Investment, jobs, and fiscal benefits

Microtransit will rewrite the value equation for downtowns. To begin with, it will enlarge the five-minute walking circle around transit stations—in essence, it will gather every downtown parcel into a transit-oriented district (TOD), adding the value premium that TOD confers. Even for downtowns without fixed transit infrastructure, any concentration of jobs, housing, or cultural amenities that attracts people today will become an asset for all of downtown as part of a single, seamless district woven together by microtransit.

Microtransit will also blow apart an unrecognized cap on downtown growth. Beginning in the 1950s, space devoted to parking and streets came to dominate downtown land uses. It ate away at amenities and pedestrian comfort, and it drove up the cost of buildable land. In essence, accommodating automobiles undercut downtown’s appeal while raising the cost of doing business there. The growth of microtransit will mean far fewer solo drivers, which will shrink roadways and send parking demand plummeting. Travel lanes will cede some space to other modes, but much new space will open for redevelopment.

Together, these changes will unlock a downtown’s ability to meet new demand, driven by demographic shifts and a changing economy. Downtown will draw a wave of new investment in housing, offices, retail, and every other use that wants to be where people are. Removing the need for onsite parking will make projects easier and cheaper to complete, while growth in amenities and pedestrian comfort will make them more valuable. Microtransit holds the key to creation of a virtuous circle in downtown economies: lower costs will encourage new development, which will put more people on the streets supporting more stores and amenities, which will in turn make more people want to live and work downtown. 

4. Equitable access

Since 2000, growth in downtown areas has increasingly come from new higher-income residents. Without a balanced and shared approach that connects all areas equally well—including neighborhoods now underserved by transit and biking—automated mobility will widen socio-economic gaps more dramatically than suburbanization did a half century ago.

Unregulated autonomy will not bring a  necessary focus on low and moderate income  neighborhoods. We’ve already seen this pattern. For example, in parts of Boston many of the market-driven benefits of shared mobility, such as car shares, bike share, and ridesharing, are poorly distributed.

Some cities have begun tailoring connected-technology policies to promote equitable mobility. Funded by a Federal Highway Administration smart cities grant, Smart Columbus will soon demonstrate the importance of spreading the four revolutions across an entire city. No municipality should sit idly by as market forces expand mobility benefits only to people with the financial or technological means to participate. Cities will need to work quickly to enact rules and regulations; pricing and taxation incentives; physical infrastructure (e.g., hailing from designated stops); and reporting and transparency requirements, to set the expectations service provides and the traveling public.

5. Addressing climate change

The greatest potential benefit of equitable dispersion of electric SAVs is a rapid reduction in greenhouse gas emissions from vehicles, now the largest single source of climate-changing emissions in the US. If autonomy leads to more sprawl-form development and travel patterns, trip lengths will wipe out many of the environmental gains from electrified mobility, especially as distance and congestion lead to greater wattage consumed per vehicle.

Unfortunately, land use policy and development regulations typically encourage sprawl, even today, and outdated traffic and parking standards often thwart compact development. Policy makers must take far bolder steps to rewrite regulations and standards to accommodate SAVs—and take those steps soon—even if that means creating zoning overlays that create consequences for using private cars; putting a price on street and curb access; or subsidizing car-free development. The long-term public cost of shared-mobility infrastructure represents a fraction of the outlay needed for wider and longer roads and utilities should single-occupant autonomy prevail—especially when we include the costs of resilient infrastructure needed to accommodate climate change. Without smart policies in place, smart organizations pushing the climate agenda, like Boston’s Barr Foundation, can only do so much.

The speed of the four revolutions has convinced many city leaders to take a wait-and-see approach, often judging autonomous pilots only through a short-term lens of jobs retention or economic development. Planners and governments urgently need to take a deep and careful look at the substantial changes in transportation and land use policy needed to avoid lasting social, economic, and environmental damage that could dwarf the effects of the sprawl we began to create in the 1950s. Shared mobility’s enormous efficiency and potential benefits for economics, equity, and the environment far outweigh the much-discussed safety value of autonomy. But shared autonomous mobility won’t happen on its own. Cities will need to rethink how they approach streets, development, and market forces. And that fundamental rethinking needs to start now.

  • David Dixon

    Residential Architecture Magazine named David to their Hall of Fame as “the person we call to ask about cities"

    Contact David
  • Jason  Schrieber

    Jason finds innovative solutions to complex mobility problems, focusing on a balance of private needs and public benefits

    Contact Jason
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