## 3 A Model for the Evaluation and Selection of the Railroad Route
### Analysis of Alternative Railroad Route Variants--Optimization Model and Evaluation
Figure 3 shows that Variant 1C differs from variant 1A on the part of the route from the Dreznica station to the Krasica station and at the junction of the new railway line with the island of Krk. In variant 1C it is necessary to build a new railway line from Krasica to Krk, and in variant 1A, the railway line to Krk is separated from the route of the new railway between the stations of Jadranovo and Krasica. The length of the route according to variant 1C is 150.1 km (section: Hrvatski Leskovac-Skradnik, 81.9 km; Skradnik-Krasica, 68.2 km). The critical section of the existing railroad line route is located between Moravice and Rijeka, on the part of the railroad route in the mountains, where it features very unfavorable elements (slope of the route 25-28 mm/m, curves 250-300 m). The problem is to be solved by building a lowland railway from Horvati to Krasica. The part of the new route from Skradnik to Krasica currently solves the problem of crossing the mountain range located between the Adriatic Sea and the interior of the country. The part of the route from Horvati to Skradnik significantly improves the route elements in comparison with the existing routes and at the same time enables the improvement, in the future, of the railroad connection to Lika and Central Dalmatia (Split, Sibenik, Zadar, and Ploce). The construction of a new route according to variant 1C solves the problem of penetration of the mountain range to the sea. All the three variants considered are suitable for this purpose, yet the variant C seems to be the most favorable one. As presented in Table 2 the economic criteria C1, C2, and C3 as well as the transport criteria C11 are expressed quantitatively [48; 49; 50]. For criteria C5, C6, C7, C8, and C18, the units of the yes/no criteria were applied, while for the eco-sociological criteria C28, C33, C36, and C37, the input parameters were from GIS (Geographic Information System), which was developed specifically for this multi-criteria analysis. Other criteria were assigned their respective parameters according to the rating scale from 0 to 10. A corresponding object function, i.e., its minimum and maximum, was also assigned to each criterion. Figure 3: An overview of variant 1C [50]. The economic criteria C1, C2, and C3 were used in accordance with the estimated financial resources [48]. Regarding railway infrastructure, the most cost-effective option is variant 1C because it requires the construction of the fewest structures. The most expensive option for the construction of the rail infrastructure and future costs of maintenance and management is the Variant 3B. Regarding criteria C21 and C22, it should be noted that variants 1A and 2A mostly pass through agricultural and forest areas. Variant 1C has the advantage for connecting the railway line Rijeka-Zagreb to the system of Croatian railroads, i.e., the railway line towards the Dalmatia region. Variants 1A, 2A, and 3B are technically and technologically highly complex with a large number of structures, viaducts and tunnels. The extremely difficult technical requirements for the connection to an open rail route would lead to higher capital expenditures, which increases the values of the economic criteria and thus disadvantages variant 3B compared to the other variants. Furthermore, according to the study evaluation, it has been accepted that variants 1A, 2A and 3B are unacceptable from an environmental point of view.