# Sustainability Analysis of the M-30 Madrid Tunnels and Madrid Rio after 14 years of Service Life
## 2 The MIVES Method and Its Application to the Renovation of the South-West Section of M-30
In addition, the non-quality costs should be taken into account, given that they are defined as those costs generated when a product of inadequate quality is obtained [60] and, consequently, increases maintenance costs [61]. So, in this case, non-quality costs were included to estimate the economic repercussions of the possible rejections and consequence of not having, for instance, a proper quality control or highly qualified and experienced labor force. As studies have shown, conventional materials are cheaper than the improved ones, though they will need a more exhaustive maintenance in the future. Equally, the purpose of the designers was to improve the environmental and social-economic regeneration of the surrounding areas of the M-30, especially with the creation of Madrid Rio [13]. Thus, the indirect economic benefits obtained from construction were, for example, the enhancement of the real-estate market and improvement of tourism in the area (Table 1). 2. Environmental requirements: the criteria and indicators studied were related to the material and energy consumption during construction, exploitation, and maintenance of the infrastructure. These criteria and indicators were focused on differentiating the use of conventional and improved construction materials. It should be noted that dosage would differ from that of conventional concretes. These kinds of concretes use a higher amount of cement (400-500 kg/m\({}^{3}\)), have a lower water/cement ratio (less than 0.3), incorporate additives and additions such as superplasticizers and silica fume [17; 19]. The nature, type and maximum size of the aggregates are also carefully studied. Equally, it has been reported that transport is a significant and increasing source of air and noise pollution worldwide [13; 62]. In particular, road transport is responsible for 93% of the environmental costs produced by traffic in Europe, which represent approximately 4% of the gross domestic product (GDP) of the area [63; 64]. Therefore, the pollutant and noise emissions during the construction, exploitation, and maintenance of the road and tunnels analyzed were also considered (Table 1). Lastly, given that one of the main goals of the renovation of the M-30 entailed linking the fluvial system of the Manzanares river with the urban landscape of Madrid [13; 65], the recovery of the Manzanares river ecosystems in the Madrid stretch of the river and related criteria was also considered. 3. Social requirements: such requirements evaluate the positive and negative effects that the renovation of the M-30 implies on workers, users, and residents of the surrounding areas on the basis of the impact on people, their community and the way of life which may occur during project design, construction, and use of the road (Table 1, [66]). Equally, the criteria were also selected by considering that roads may produce direct or physical and indirect or physiological effects on workers, users and residents [67]. Therefore, social criteria with these direct or physical effects were those related with health and safety, such as air and noise pollution or accident rates (Table 1). By contrast, social criteria with indirect or psychological effects were, for example, those related with traffic and people fluency, travel time, and accessibility (Table 1). Once the requirements, criteria, and indicators are established (Table 1), the value functions for each indicator should be defined. Value functions convert the criteria magnitudes and units into a common, non-dimensional value [22] and delimit the units of the function. In this case, indicators would take values between 0 and 10, with 10 being the highest degree of social satisfaction and sustainability and 0 the lowest. Lastly, the SI of each alternative of the M-30 considered: that is to say, non-buried, buried by using conventional materials and buried by applying new materials as calculated with Equations (1)-(3) [22]. The value of a generic criterion (\(V_{Cj}\)) is supplied by Equation (1).