Transport challenges in rapidly growing cities: is there a magic bullet?

Rapid population growth in major cities of the world

More than half of the world’s population now lives in cities, and projections indicate that urban areas will account for 60% of global population by 2030. Cities are growing in number, population and land area. In 2018, there were 548 cities with at least 1 million people, and that number is expected to grow to 706 cities by 2030. Similarly, the number of cities between 500,000 and 1 million people is expected to grow from 597 to 710 from 2018 to 2030. The average annual rate of total population growth for all cities over 500,000 was 2.4 percent between 2000 and 2018, including 36 cities with average growth rates of more than 6 percent per year (United Nations, 2018). While land area for the city proper has generally remained the same, land areas for urban agglomerations and metropolitan areas have grown considerably. Simply put, more people are living in more and larger cities.

Declining performance of urban transportation

It should come as no surprise that increasing population in cities is straining urban transportation systems. People who live and work in the major cities of the world are faced with increasing levels of congestion, delays, total travel time, costs, frustration, accidents, and loss of life. According to the INRIX (2018) Global Traffic Scorecard that analysed congestion and mobility trends for over 200 cities across 38 countries, over half of the cities registered over 100 h lost in congestion per driver per year. A recent survey found that average commuting time is more than 1 h each weekday for workers in 41 out of 52 countries (Holmes, 2017). Congestion costs in the United States were estimated at nearly $87 billion, or $1,348 per driver, while for the United Kingdom, congestion cost drivers £7.9 billion, an average of £1,317 per driver (INRIX, 2018). Road traffic crashes, many of which occur in urban areas, claim the lives of 1.35 million people per year. More than half of all road traffic deaths are pedestrians, cyclists, and motorcyclists (World Health Organization, 2018).

Adding to these concerns is the overarching issue of climate change and greenhouse gas (GHG) emissions. As David Banister (2019) has recently noted, global CO₂ emissions are rising again and targets for 50% carbon emission reductions by 2030 and net zero by 2050 that would be needed to meet the 1.5°C Paris Agreement goal will be harder to achieve. The decision by President Trump to withdraw the United States from the Paris Agreement compounds the problem. Transport is one of the major contributors of global GHG emissions, and in the US it is now the largest sector accounting for 29% of GHG emissions. As cities continue to grow in population, they find themselves on the front lines of efforts to mitigate climate change. Many cities have taken the initiative by enacting ambitious climate action plans (CAPs) to reduce GHG emissions, including Barcelona, London, Paris, Cape Town, and Hong Kong that recently received top ratings for their efforts (CDP, 2019). While progress is being made to introduce more renewable energy into electricity production, buildings and industry, urban transportation remains a problematic area even though many cities are trying to transition away from fossil fuel use in motor vehicles, and encouraging more transit, cycling, and walking.

What is to be done?

Given the magnitude of the urban transportation problems, and projections for continued city growth, the challenges for addressing current and future needs are daunting. In the public conversation about fast-growing cities and transportation challenges, it appears that two general approaches have emerged. The first could be considered an incremental progress approach that emphasises the expanded development of multimodal mass transportation technologies to try to accommodate increasing volumes of passenger and freight movement in cities. Learning both positive and negative lessons from our largest cities, this approach seeks to develop transportation systems emphasising mass transit in a variety of forms (local buses, express buses, bus rapid transit, commuter rail, subways, light rail, trams/streetcars, jitneys, ferries, etc.), as well as walking and cycling, and discouraging single-occupant automobile use. Alternative methods of urban goods movement including smaller delivery vehicles, designated freight delivery areas and urban consolidation centres are being implemented in large rapidly-growing cities. Promoting automobile traffic-free zones and congestion pricing as well as reducing the number and length of trips are also important elements.

The second general response could be called the magic bullet approach that relies upon an expected promise of new technologies which will revolutionise urban transportation. Growing frustration with worsening congestion, delays, and costs of contemporary urban transportation has led to the search for the magic bullet – the golden set of technologies that will solve urban transport problems in one fell swoop. Especially in rapidly growing cities, the travelling public has become extremely dissatisfied with the current state of transportation and yearns for traffic solutions that can be implemented quickly. Anticipation and “buzz” over the deployment of automated and connected vehicles in the near future has raised expectations that these and other technologies will transform mobility and transcend the problems we experience today.

Automated vehicles (AVs)

Much has been written and said about the potential for AVs and driverless operation to become the breakthrough technology that will revolutionise transportation. Expected benefits of AVs include greatly improved safety, increased accessibility, reduced congestion due to more efficient use of road space from connected vehicle technology and the possibility of greater car-sharing offered by mobility companies, less need for roadway infrastructure and parking, and overall lower costs. If most AVs will be electrically-powered, accompanied by the continuing shift to renewable energy sources, they will be cleaner too.

In his book Three Revolutions: Steering Automated, Shared, and Electric Vehicles to a Better Future, Daniel Sperling (2018) depicts two different scenarios for the future of automated transportation. The Dream scenario envisions that transportation will be provided by electrically-powered AVs owned by mobility companies delivering shared services. People will be able to spend more time with family and friends rather than being stuck in traffic congestion because of improvements from pooled automated cars. The number of vehicles on the road and GHG emissions will be reduced significantly. Mobility will improve greatly for all members of society including the young, old, poor, and disabled. And traffic accidents and fatalities will be largely eliminated.

The Nightmare scenario envisions that communities are unprepared for the three revolutions, allowing most AVs to be non-electrified and privately-owned with limited pooling. GHG emissions rise significantly and traffic congestion is much worse as many more AVs take to the road, some circulating with no passengers. Leisure time and mobility for underserved populations decrease, while travel time, commuting distances, urban sprawl, infrastructure needs, and costs increase even more. Sperling notes that while it is inevitable that most cars will eventually become automated, it will be up to communities to enact regulations, policies, and incentives to encourage pooling, electrification, and other adaptive measures so as to avoid the nightmare scenario.

Embrace of the technological fix

When new revolutionary technologies are being developed, with expectations of major improvements over existing conditions, there is a tendency to become overly enamored with the new technologies and sometimes blinded to their potential pitfalls. Societies have been inclined to embrace the technological fix, oftentimes accompanied by the encouragement of industry boosters who hype expectations.

The twentieth century history of the innovation and diffusion of automobiles and proliferation of highways in the US are good examples. The internal combustion engine automobile was a major improvement in speed, accessibility and convenience over existing transportation technologies in the early 1900s. Its popularity spread with the application of assembly line techniques which resulted in the production of many more affordable cars. In order for the automobile to be used most effectively and to improve sales, new roads and highways specifically designed to accommodate the car needed to be built. This required the support of government and the general public to provide political backing and funding for new roads and highways.

At the 1939 World’s Fair in New York, General Motors sponsored Futurama, an exhibit designed by Norman Bel Geddes that portrayed “Cities of Tomorrow” featuring modernised freeways with free-flowing traffic speeding through cities as part of a “National Motorway System”. This exhibit, viewed by millions of people, had an enormous impact in creating a technological vision of the future that was embraced by the public and ultimately resulted in the construction of the US Interstate Highway System. In his book, Magic Motorways, Bel Geddes (1940) promoted the advance of technology by linking the nation’s urban future to the automobile and the freeway (Mohl, 2004). Even though public works builder Robert Moses responded to the public demand for more highways by leading these efforts in New York and other cities, he dismissed Bel Geddes as a melodramatic dreamer: “The Futurama sold cars, but solved no highway problems and, if anything, made the task of the road builder tougher because the public was taught to expect magic” [emphasis added] (Moses, 1946, p. 8; cited in Mohl, 2004).

The legacy of automobile proliferation and massive highway building in the US has led to many unanticipated problems in urban transportation. After many years and much investment, observers began to realise that the US automobile and highway system created enormous negative externalities and incompatibilities for large, rapidly-growing cities. Unfortunately, much city growth occurred under the hegemony of the automobile and highway system creating a low-density sprawling pattern of urban development and extreme automobile dependence that has caused and exacerbated many urban transportation problems.

Local experience

I can’t help but think about the current state of urban transportation in my home city of Denver, Colorado USA. With a metropolitan area population of approximately 3 million, Denver is categorised as a medium-sized city by the UN. It has been experiencing rapid population growth, at least compared to other cities in the US, and has been beset by mounting concerns over the functionality of its current and future urban transportation. Despite investing in a new regional rail and expanded bus system, as well as encouraging more walking, cycling, and transit-oriented development, the metropolitan area mode share for active travel (transit, walking, and cycling) is stuck at only 7% compared to 76% for driving alone. Vehicle miles travelled per capita, which had been declining from 2006 to 2014, is rising again, along with increasing traffic congestion, travel time, costs, accidents, and fatalities. Given these negative realities and frustration with the lack of progress, it is tempting to embrace the magic bullet of AV technology that holds the promise of solving these problems once and for all.

Lessons for the future

Although tempting, it is nevertheless important to heed the lessons of history, and not be blinded by the shiny new object. It may be that AVs will result in real and substantial improvements in urban transportation, but how cities decide to introduce and integrate them into their transportation systems will be more critical than the technology itself.

The incremental progress and magic bullet approaches are not mutually exclusive, and in fact, may work well together. It is possible and perhaps preferable to adopt a sequential hybrid strategy that continues incremental progress in the short term while also preparing for the magic bullet technology with a clear awareness of its potential promises and pitfalls. Indeed, most transportation planners thus far seem to be adopting a “watch and wait” approach with regard to AVs and long-range planning (Guerra, 2016; Milakis, 2019). There are times when incremental progress may seem slow and ineffective, while the lure of the technological fix can be enticing, especially in rapidly-growing cities facing extreme transportation challenges. But it is possible that the magic bullet may never happen, that it will always be just over the horizon, so continued incremental progress is essential. Making sure to base decisions on real progress in addressing sustainability in safety, environment, equity, and efficiency will help to provide the vision needed for the future of urban transportation.