Road interchanges with minimal numbers of bridges
Road interchanges with minimal numbers of bridges
What is the smallest number of bridges necessary to build a complete n way road interchange where changing lanes is not allowed? According to the paper On the genus of the complete tripartite graph K(n,n,1) (https://arxiv.org/abs/1612.07888) by Valentas Kurauskas, the answer for even values of n is given by (n–1)(n–2)/4, after rounding up fractions.