2023-08-29 A (a,b) vs B (c,d) - a>c를 위한 e를 찾아! a->e->[b<<d]로 a+c < b+d주장 Critics, however, question whether PRT systems are practical. Small PRT vehicles are most suitable for situations in which there are relatively few passengers going to each destination. But PRT guideways are complicated and expensive to build. Economically, they would make sense only for heavily traveled routes. Yet for routes within cities, where passenger volume would be high enough to cover the cost of building the guideways, the small cars would not be large enough to carry many people. Outside of city centers, construction of PRT systems would not be cost-effective due to the number of guideways that would be needed. These are serious problems that need to be solved if PRT systems are to be a realistic public transport option. 단위비용 싸다. 작다. 고정비용 생각했어? 그게 작은거에 침해?? 높은 고정비용으로, 높은 수요지역에만 설치될 것 (wo.gov). capa한계. 단위비용 안 싸진다.