Why sitting in bumper-to-bumper traffic is becoming more of a headache

Think traffic is bad in New York or London? They ain’t got nothing on Jakarta and Chongqing.

The top of TomTom NV’s ranking of the world’s most congested places is dominated by emerging markets. Among cities in rich countries, only Los Angeles makes it into the top 15.

Some of the world’s worst traffic snarls are in South Asian cities not even picked up by TomTom’s ranking, such as Dhaka, Delhi and Karachi. Their problems are only likely to get worse as growing populations and rising incomes push already-straining transport networks to the limit.

In emerging economies, many cities have reached the point where roads’ carrying capacity is running out. There are about 40 registered vehicles for every kilometer of road in the US, France, Russia and Brazil, based on analysis of World Health Organization and Central Intelligence Agency data. That compares with Iran, Thailand, Vietnam and Indonesia, which are all north of 200 vehicles per kilometer. It’s hardly an accident that the traffic jams in Tehran, Bangkok, Ho Chi Minh City and Jakarta have become so legendary.

Two factors have made this just about manageable, for the time being. First, fewer people own vehicles in poorer places: There are just 13 registrations per 1,000 people in Bangladesh, 30 in Nigeria, and 44 in Pakistan, compared with more than 500 in most wealthy countries. And when people in low-income regions do get their first vehicle, they tend to be motorbikes and scooters, which take up less space than passenger cars.

Both those mitigating issues are less helpful than they look. For one thing, as incomes rise, vehicle ownership does, too. For another, two-wheelers still require surrounding space to avoid collisions. Scooters and motorbikes on the move take up about half the space of a car. That, alongside the exhaust fumes they spew, helps explain the motorbike bans already implemented in parts of Jakarta and Manila and planned for the entire city of Hanoi by 2030.

One way of stemming this flood has been restricting vehicle usage. Road-space rationing programmes, which ban driving for some cars on particular days, have been implemented in cities from Manila and Mexico City to Bogota and Beijing. London charges for entry into the central city, which has a similar effect.

Alternatively you can limit car numbers by mandating special permits for car ownership and using auctions or lotteries to allocate a fixed quota. First established in the 1990s by Singapore, these systems have since spread to more than half a dozen Chinese cities, including Beijing, Shanghai, Guangzhou, Shenzhen, and even the comparatively sleepy outpost of Guiyang.

Then there are more free-market solutions that have attracted the most investment dollars and interest in recent years — ride-sharing and autonomous driving. These aren’t likely to make a decisive difference. Studies of ride-hailing services such as Uber and Lyft suggest they may encourage some people to give up on owning their own vehicles — but they also tempt riders away from higher-capacity public transport modes.

Autonomous vehicles could, in theory, increase road capacity by using shorter stopping distances than would be safe with human drivers. But for the moment such technology remains science fiction, especially in the complex, dynamic streetscapes of emerging-world cities crowded with scooters, hawkers, pedestrians, tuk-tuks and livestock.

The solution that’s likely to be the most effective in the long term is also the most drastic: An expansion of public transport — in particular metro and suburban rail networks that remove traffic from roads altogether.

Luckily, that’s already underway. The world will add about the same length of metro-rail tracks in the 10 years through 2022 as it built in the previous 150 years since the opening of London’s Metropolitan Railway in 1863. China’s metro systems have expanded at breakneck speed this century, and India is gradually catching up. Even laggards like Dhaka, Jakarta, Lahore and Lagos are finally building dedicated commuter-rail networks. It’s unlikely to be enough, though.

Take Beijing. If any city should be able to meet the demands of transporting a fast-growing urban population, it’s the showpiece capital of the most ambitious infrastructure-developer the world has ever seen. And yet the city is still bursting at the seams, despite road-space rationing; vehicle quotas; a brand-new metro system that carries more passengers than New York and London put together; and longstanding hukou restrictions on residency.

The city governments elsewhere in the developing world will find it a lot harder to accommodate their swelling populations without grinding to a halt. If you want a vision of the future, imagine a boot idling on a brake pedal while stuck in traffic — forever.