Braess’s Paradox and Beijing Traffic Congestion
https://www.chinadaily.com.cn/business/motoring/2016-01/04/content_22920572.htm#:~:text=The%20commission%20has%20set%20a,transport%2C%20bicycle%20or%20on%20foot.
Beijing, among other capitals like Korea’s Seoul and Egypt’s Cairo, is one of the most crowded capitals in the world with terrible traffic. A regular 2-mile distance drive can take up to 1 hour. The most obvious cause of the congestion is the fact that the capital is overcrowded. However, the lesser-known fact is that the city’s roads are poorly regulated. The locations of the office buildings are all centered around a specific district in the city center called Haidian, and the residents’ community are scattered in the outer circles of the city. During morning and afternoon rush hours, people are all headed towards the same direction, which leads to severe traffic jam.
The city has come up with many strategies to deal with this condition, including building more roads to incorporate the large number of vehicles, encouraging citizens to take public transportations, and imposing restrictions on the use of private vehicles at specific times. The latter two approaches led to slightly better conditions, and building more roads only made the issue worse. This reminds me of one of our class topic’s of Braess’s Paradox: adding one or more roads to a road network can slow down overall traffic flow through it. There will be a unique nash equilibrium in the new network with the added highway, and it leads to longer travel time for everyone. The logic behind is actually simple: individuals would think that the new roads are faster and they all rush into them, leading to worse performance. As a result, the best way to alleviate the stress of congestion in a traffic network is not by facilitating the use of it but by reducing the use of it.
