Why UPS Drivers don’t turn left and the Driver’s Dilemma
Although atypical, UPS delivery vans do not always take the shortest routes between stops. The company gives strict orders to all drivers that the drivers should never drive through oncoming traffic. In America, this means turning left. UPS drivers do not turn left onto oncoming traffic unless absolutely necessary. This means the company prefers the drivers to take the longer route as long as they do not make a left into oncoming traffic. Involving themselves in the vehicle routing problem, UPS has given up on finding the shortest path and looks at other criteria to optimize their journey. Since only 10% of all turns are left turns, the company is actually saving 10 million gallons of fuel and emits 20,000 tons less of carbon dioxide and delivers 350,000 more packages a year by avoiding left turns. By reducing the chances of an accident and cutting the delay of waiting for a gap in the traffic, UPS is improving the environment in each delivery!
So why doesn’t everybody else follow this pattern and save fuel altogether? This introduces the concept of the Driver’s Dilemma. Everybody looks for their own benefits in every situation. If everybody else followed this rule and only turned left when necessary, the environment would improve and everybody would benefit from this system. However, if there few people that do not cooperate, then the whole system would break down and the implementation would be unsuccessful. This concept relates to Prisoner’s Dilemma and Nash Equilibrium, which were two topics that were covered in our lectures. In the game, the Prisoner’s Dilemma, if everybody cooperated, then the system would be better and there is a chance for improvement and mutual benefit for everybody. However, the best thing for an individual would be to not cooperate when everybody else is cooperating to reap the benefits of other’s sacrifices. Thus, for the UPS vehicle improvement system to work for everybody on the road, a person would need to develop a clever plan, so everybody would have to cooperate and the entire country would prosper. It is interesting to see how even the tiny decisions we make while driving have a huge impact on our ecosystem and the country’s prosperity.
Link to original article: https://theconversation.com/why-ups-drivers-dont-turn-left-and-you-probably-shouldnt-either-71432