Why do we still have so much traffic?

Flash forward. The year is 2050 in Los Angeles, a city that consistently ranked with the worst traffic in the country a decade a go. Now, smart roads and bridges have not only become the standards of innovation, but also the pride of our nation. They interconnect cities and sprawl across towns with flows of people, goods, and services. Urbanites now enjoy unencumbered rush hour commutes, safe pedestrian crossing, and a truly beloved transportation system. In recent years, drivers have seen average transit times reduced by half. Leveraging the same innovations across the nation, roadway congestion that accounted for ~$100 billion a year has now reduced by nearly 50%, fallen from its peak through the recovered fuel, time, and productivity. The once ballooning traffic fatalities, about 33,000 fatalities a year, no longer drains the economy another ~$100 billion a year on medical expenses and civil penalties. Urban centers that were taken up by parking space have now been consolidated through shared economy. It nearly tripled the occupation rate to 85%, better serving drivers that used to circle endlessly around city blocks for such mundane task. This alleviated subsidized public parking and cities around the country recovered another stream of revenue worth ~$100 billion a year. The new infrastructure initiatives taken 30 years ago have helped cities adapt to urbanization through a concept called the “Smart City”. The progress has made urban life even more alluring to its inhabitants. New public policies such as universal healthcare and guaranteed basic income were adopted without the scrutiny.

Is this image within the trajectory of our future? Regardless, it is certain that our crumbling infrastructure presents an insatiable opportunity for improving our transportation system. So why are things getting worse?

US urban traffic delay in annual hours based on city size (1980-Present)

One reason is that the high cost of new construction makes quick, equitable progress difficult (~$100 million per mile for both highways and rails). The slow timetable is exacerbated by the need to balance spending on new, capital-intensive projects versus maintaining a broader proportion of existing stock. The need to build and maintain roads has outpaced the available budget and resources. From 2004 to 2008, states on average dedicated 43 percent of their road budgets to maintain existing roads despite the fact that they made up nearly 99 percent of the road system. The other 1 percent — new construction — got more than half the money. From 2009 to 2011, that ratio stayed much the same, 45 percent ($16.5 billion) to 55 percent ($20.4 billion), respectively. As a result, the spending shortfall has only slowed the erosion of our infrastructure. To fully meet the need for repairs, according to Smart Growth America, the country would have to spend 3 times as much to the tune of $45 billion a year. The lack of resources needed for new construction faces another set of challenges, ranging from inequitable tax spending to causing gridlock to local streets.

The urban network effect: ~15% increase in productivity for every population doubling

Another reason for having endless traffic is with entrenched mindset. Since the 1980s, traffic congestion has tripled the average traffic delay across US cities. The increase is seen across population centers, regardless of city size, ranging from the very small (< 500,000) to the very large (>5 million). Moreover, longer transit times are experienced by inhabitants in larger cities. But wait a second! Shouldn’t large cities be more efficient at providing basic goods and services like mobility? Isn’t that’s why people flock to cities? Yes, says theoretical physicist Geoffrey West, who proposed a “grand, unified theory of cities”, claiming: If a city doubles in size, then, all else being equal, a whole range of things become more efficient. Productivity in wages, for example, will increase by around 15 percent with every population doubling. The same in reverse will apply to gas stations, leading to less per person with larger cities. The correlation lies in the idea that when people, businesses and infrastructure reside in one place, the collective output is greater than the sum of its parts, resulting in greater productivity per capita and efficiency.

Or, does it? Looking at the transit delay data, the exactly the opposite occurs. The average driver stays in traffic 20–25% longer for every population doubling. In fact, drivers are willing to pay extra for the commute. Labeled as the “commuting effect”, economists have observed that for every additional 45 minute spent on the road, employees are willing to take a 20% pay cut. Aside from the dreaded rush hour, this equivalence also points to the inadequacies of public transit. People rather put up with lower wages than taking a bus or a train to work. Personal time is valued in real dollars, significant real dollars, regardless of the mode of transit. It is also dragging down the economy, which is worth $300 billion a year in the US in lost productivity, medical expenses, and legal fees. If there is one reason that productivity is not higher in our cities, it is because of our poor transportation system.

The familiarity of traffic horrors makes the trend perhaps more intriguing than surprising. Shouldn’t travel times reduce as more people and businesses reside near one another? In 2015, two-thirds of people living in the US took up just 3.5 percent of the land area. It make everyday living more convenient but at a price: more traffic and less mobility.

As counter-intuitive as it sounds, perhaps urban commute lacks the network effect seen in other goods and services. That is, people and businesses have more opportunities to share ideas and collaborate on projects in an urban environment. But cars and roads certainly don’t (at least not yet). But gas stations don’t talk to each other, either. Likewise, the total length of electric power cables needed also reduces on a per capita basis exactly matching West’s theory. It seems those things which make cities efficient do not apply to personal mobility.

The inadequacies of our approach to urban mobility are pervasive to even the lowest hanging fruit. By estimate, as much as 30% reduction in urban traffic can be realized if parking spaces can better serve the public. As it stands, providing urban parking is both expensive and inefficient. By account, our country spends $250 billion a year just on parking subsidies that is both unfair and unsustainable — on par with the national spending on both healthcare and the military. The problem is deeply rooted in the out-dated regulations. According to the American Planning Association, cities set parking requirements for at least ~650 different land uses (e.g., 1 space per every patron and employee for restaurant ). One such requirement is for nunneries with 1 space for every 10 nuns. To see the result of these regulations, below is a birds-eye view of the land allocated for parking in Buffalo, NY. The result is that 90% of all public and private parking spaces are free at all times in cities such as San Francisco, which has ~440,000 publicly accessible spaces available. At a cost of $28,000 each, there is a lot of expensive unoccupied spaces worth its area painted in gold.

Parking spaces allocation in downtown Buffalo, NY.

Despite the billions spent, the effort has not been able to reverse the dwindling level of service to the public. There are exceptions, however. One is exemplified by simply coordinating traffic signals — referring to the timing of the signals so that a “platoon” of cars arrives at a succession of green lights and proceeds through multiple intersections without stopping. First deployed in the 1960s by Henry Barnes, coordinated traffic signals were used in New York City but only adopted by Los Angeles 50 years later. In 2013, California’s Los Angeles County synchronized all its 4,500 traffic lights over its 469 square miles. The resulting benefits, by estimate, account for an annual saving of $1.3 billions (≈$100 per registered driver). This breaks down into 31.3 million hours of travel time, 38 million gallons of fuel, and 337,000 metric tons of carbon dioxide. Impressive, consider all this for a city with 15 million inhabitants. Imagine the potential socio-economic impact if more traffic signals in cities were coordinated. The return on investment, though, is vastly different given the method or approach.

Mobility, efficiency and accessibility are all adversely impacted by poor urban planning. There are less acute, but equally expensive, problems though. These include the ones related public health and even the overall well-being of urban dwellers. Together, they represent opportunities for change and the impetus for improving urban transportation. At a minimum, the solutions to our traffic woes should have these considerations:

  • Capital efficient solution that represent a fraction of the cost of new roadway expansion
  • Accelerated timetable with upgrades that does not require expansive land acquisition
  • Lower operational cost without burdening local governments with expensive maintenance
  • Energy sustainability that adheres to the carbon reduction goals set for existing vehicle fleets
  • Taxpayer appeal from having a low-cost solution that is equitable to all inhabitants

Such challenges must be met by new and intelligent solutions, not brute force. And some of them have already been effective for cities around the world and should be examined carefully for our own. The future has already been invented, as they say; it just has not been distributed evenly.