On this urban road, what is the maximum speed at which we may travel in the absence of specific signage?

The general speed limits on urban roads, depending on the characteristics of the carriageway, are as follows: a) 20 km/h on roads with a single shared platform for carriageway and pavement. b) 30 km/h on roads with a single lane per direction of travel. c) 50 km/h on roads with two or more lanes per direction of travel. (40 km/h for vehicles transporting dangerous goods) For these purposes, lanes reserved for the circulation of certain users or for the exclusive use of public transport shall not be counted. These limits may be reduced or increased by the Municipal Authority subject to specific signage. On through roads, a limit of 50 km/h is set for all types of vehicles, except for vehicles transporting dangerous goods, for which it shall be 40 km/h. This limit may be lowered by agreement between the Municipal Authority and the road authority, subject to specific signage.