Here, two very much related papers, albeit the title of the first one wouldn't tell you that: https://arxiv.org/abs/1612.07888 https://arxiv.org/abs/1612.07888

Here, two very much related papers, albeit the title of the first one wouldn't tell you that: https://arxiv.org/abs/1612.07888 https://arxiv.org/abs/1612.07888 Kurauskas, Valentas - On the genus of the complete tripartite graph Kn,n,1 [2017] https://arxiv.org/abs/1801.03860 https://arxiv.org/abs/1801.03860 Kurauskas, Valentas; Šiurienė, Ugnė - Symmetric road interchanges [2018] And slides from 2010: http://web.archive.org/web/20101127223543/http://www.saga-network.eu/phocadownload/auron/Krasauskas.pdf http://web.archive.org/web/20101127223543/http://www.saga-ne...