Table 1. Principal characteristics of the networks under study, ordered by decreasing population²⁹,³⁰,³¹,³²,³³,³⁴,³⁵,³⁶,³⁷.

City	Layers				Nodes	Links
	Bus	Metro	Tram	Tot.
London	541	11	3	555	19459	43614
Berlin	151	22	10	183	2866	9079
Madrid	177	16	3	196	4703	9176
Barcelona	97	11	6	114	2512	5337
Valencia	46	6	3	55	1228	2617
Zaragoza	35	0	1	36	915	1550
Malaga	41	2	0	43	1034	1876
Bilbao	35	2	1	38	555	1212
Vitoria	14	0	2	16	302	452