Speeds associated to the upper categories were not considered, assuming that, in general, they correspond to roads with separated lanes and less inclined slopes, which due to their design, do not induce the same phenomena as two-lane roads do.
Las velocidades asociadas a las categorías superiores no se consideraron asumiendo que, en general, corresponden a vías con calzadas separadas y pendientes menos inclinadas que por diseño no inducen el mismo fenómeno que en caminos bidireccionales.