I recently went on a trip with my wife that included stops in Bangkok and Hanoi. Both of these cities share a common love of motor-scooter transportation. However, scooters are a hot topic in many major Asian cities as they balance fuel efficiency and pollution. What role should these motor scooters play in the cities of the future? 

About 16 million people live in the Bangkok metropolitan area, making it the 17th largest city in the world. Unlike most North American cities, major intersections in Bangkok are filled with motor scooters. Many of these motorbikes have small, two-stroke engines. The scooters weave through car traffic the way sand filters below larger rocks when sifted. 

Small enough to go between cars and on road shoulders, scooters pile up at the front of the intersections. When a light turns yellow, it is hard to tell what the scooters will do next. Some scooter drivers anticipate the green light and dart across six lanes of traffic to get an early start, while others know they have a second to zip across oncoming traffic to get where they want before someone else gets the green. The result is a brief multidirectional melee before the normal intensity of traffic starts again.

Why are motorists so eager to dart across traffic? According to research conducted by TomTom, the GPS manufacturer, Bangkok is the second-most congested city in the world, behind Mexico City. Bangkok leads the world with the highest evening peak traffic increase when compared to the same, noncongested roads. 

Congestion isn’t the only transportation issue Bangkok is currently wrestling with. Fine particle pollution was such a problem during one of the days we were in Bangkok that they canceled schools in the downtown area. PM2.5 fine particle pollution was the driver of the school cancellation and the reason why many residents now wear special medical particulate masks to walk around outside. 

PM2.5 refers to particles of many different combustion processes (e.g., motor vehicles, power plants and wood burning) that are 2.5 micrometers in diameter. To put 2.5 micrometers in context, more than 20 of these particles stacked on top of each other still wouldn’t be as tall as the diameter of a strand of human hair. 

These small particles are especially concerning in large concentrations because they can irritate your eyes and throat at a minimum and trigger asthma attacks, reduce lung function and even cause heart attacks in more serious cases. 

Two-stroke scooter motors can be very fuel-efficient. From one angle, a scooter that may get nearly 100 mpg is a much more energy-efficient choice than a car to move a single human around. However, two-stroke scooter motors can produce enormous amounts of PM2.5 particles when compared to a modern car engine. The Telegraph notes: “Two-stroke scooters contribute to around 60 [percent] of roadside POA (primary organic aerosol) pollution in Bangkok, where they account for 10 [percent] of the fuel consumption.” 

It seems clear that the use of two-stroke scooters may reduce the number of cars on the road. However, they escalate the PM2.5 problem in the city. The battle in Bangkok, as in most major cities, will be to shift more commuters to mass transit to make a meaningful, long-term improvement in the PM2.5 pollution and congestion.

Investing in public transportation

Like Bangkok, Hanoi also is packed with scooters. The city of Hanoi has a population of around 7 million. When we first arrived, like most western tourists, we stood in awe of the traffic zipping through intersections, fearing for our lives as we crossed the street. And as in Bangkok, there seemed to be a soft set of rules for traffic patterns. 

What’s different about Old Quarter Hanoi is that all the streets are fairly small, so nobody is going very fast, which makes it more of a free-for-all. Many intersections don’t have any stop signs or lights; the individual or group of motorists who want it the most have the right of away, essentially. It is like a school of fish swimming through another school of fish. 

In Hanoi, some officials are looking for a future without scooters. The Guardian writes of an interview with Vu Van Vien, the Hanoi Department of Transport director: "The department of transport and the city council have agreed to ban motorbikes and scooters by 2030 to ease congestion and air pollution. Citing an ‘alarming’ increase in the number of two-wheeled vehicles — traffic is at nearly four times the capacity of roads in crowded areas — the government has decided to invest heavily in public transport instead.”

Vein continues: “If rates were to continue as they have been, then by 2030 we would have 1.9 [million] cars and 7.5 [million] motorbikes on the road — but there’s conflict between the development of our infrastructure and the transportation needs of our residents.” 

It will likely take a lot of convincing to get Hanoians off the scooters and into public transit because the scooters are an extension of the lifestyle that makes the city fun and fast. Everybody we asked about the scooter ban rolled their eyes, similar to if you asked someone in the state of Texas if the whole state would stop playing football. 

While scooters may be fuel-efficient, the high PM2.5 emissions may outweigh the high mpg average in these large cities. It doesn’t mean the car is a better choice because automobiles take up so much more space on the roads and in parking lots and aren’t as energy efficient. The bigger question is what would it take for Bangkok, Hanoi and other major cities like them to give up their scooters for something else?

The World Health Organization states that more than 7 million people a year die of exposure to indoor and outdoor pollution. Two-stroke scooters may play a major role in this pollution in cities. Yet millions of people have purchased scooters to improve their daily lives. Inexpensive scooters are a way for many to live further away from a mass transit hub and still get to work on time and have time to spend with their families. 

It will be interesting to see where the scooter debate goes over the next decades in megacities as the balance between health and convenience makes for a passionate argument. 

For more information, visit these websites:

• Bangkok air pollution: https://cnn.it/2GcVI55
• Hanoi motorbikes: https://bit.ly/2vy6Txw
• Scooters pollute more than cars: https://bit ly/2Uy7E5T
• Particle pollution explained: https://bit.ly/2MdguTd
• The largest cities in the world, as of 2018: https://bit.ly/2UBLCiM
• TomTom traffic index: https://bit.ly/2naylR5
• Air pollution info from the World Health  Organization: https://bit.ly/2TBWWPv