This system would have advantages in central city areas with high-rise buildings. The streets would not be affected by such beams, but buildings would have to be adapted to harbor terraces on roofs or at suitable floors. Or, the beams could enter the buildings through the walls. . Alternative b is the smoothest of all solutions and, next after a and c , the cheapest. Alternative c is not a bad solution at all.
Alternative d is an excellent solution, when it can be used.
Alternative e is the most awkward and expensive solution. But, granted, an interface with existing railways is desirable, and if those platforms are too narrow to accomodate the beamcars, the depicted solution is viable. Alternative f is the option for brave-hearted architects who can get the ear of the boss and the customer. Many streets, especially in the central part of this city, are so narrow that motor vehicle traffic cannot get through if people park their cars on both sides of the streets. And park they do.