Choice of road building technology - statistic analyses with the use of the Hellwig method

. There are two technologies for road construction, e.g. an asphalt one and a concrete one, that exist in the market of road infrastructure at the moment and they both have their advantages and disadvantages [prof Jan Deja of Krakow Mining Academy, Cathedral of Building Materials Technology].The advantage of concrete pavement consists of the fact that it doesn’t require bigger financial expenditures within 10 – 20 years of exploitation (provided that necessary pavement maintenance treatments are carried out). In the case of asphalt pavement it is necessary to mill the wear off layer of the road already after 6-7 years. It leads to the question: which of these technologies should be chosen, which is better? The work hereby carries on analyses concerning a comparison of the technologies for road constructions; the asphalt one and the concrete one. Based on the analyses carried out with the use of the Hellwig method it was found that the achieved values of synthetic meters for asphalt and concrete pavements are close to each other, which may indicate that both technologies are comparable within the sectors taken for analyses in relation to accepted technological-technical and usability features.

Their duties include: -preparation of projects for road network development plans and projects of plans for financing the building, re-building, repair, maintenance and protection of both the roads and road engineering objects, -performing investment functions, -keeping a record of roads, working out information about public roads and sending them to the General Director for National Roads and Motorways, -carrying on periodical control of the condition of roads and road engineering objects with regard to their influence on the security of traffic, including the verification of features and pointing out defects which require either corrective actions or maintenance work because of the security of the road traffic.
-analyses of the influence of road work and safety of road traffic, -issuing permission for lane occupation and exits from roads, as well as collecting tolls and fines.

Categories and classes of roads
The road category is connected with its function in a road network in Poland. The Bill of Public Roads [2] distinguishes the following road categories: state roads, provincial roads, district roads and community roads. A road included in one of these categories, in the understanding of Bill [2] of Public Roads, must meet the technical and usability requirements determined for the following classes: -State road -A (motorway), S (express road) or GP (main road for accelerated traffic), -Provincial road -GP (main road for accelerated traffic) or G (main), -District road -GP (main road for accelerated traffic) , G 9 main) or Z (collect), -Community road -GP (main for accelerated traffic) , G (main) , Z (toll) , l (local) or D (access roads).
The class of road determinesthe technical and usability requirements. The decree of the Minister of Infrastructure of March 2, 1999 concerning technical conditions to be met by public roads and their location (Dz, U. No 43, pos. 430, with later amendments) introduces the division of roads into the following classes: motorways, express roads, main roads for accelerated traffic, main roads, toll roads, local roads and access roads.

Financing of roads
Assignments concerning road building, re-building, repair, maintenance, protection and administration and financed by: -Minister responsible for road transport via General Director for National Roads and Motorways in relation to state roads, -Provincial self-government administrator in relation to province roads, -District administrator in relation to district roads, -Community administrator in relation to community roads.
Within the borders of bigger towns, assignments connected with financing road building, re-building, repair, maintenance, protection and the administration of public roads are paid out of the budgets of these towns. The financing of building, re-building, repair, administration and the protection of private roads is done from the money of their administrators [3,4]. At present, the General Director for National Roads and Motorways plans to build about 860 km of roads with concrete technology until the year 2020. In 7 years the share of concrete in fast road networks will increase from 18% to almost 27% [4].
Nowadays, two road building technologies exist in the road infrastructure market: an asphalt one and a concrete one. They are both necessary, and each of them has its advantages and disadvantages [5][6][7][8][9][10][11][12][13][14][15]. The advantage of a concrete structure lies in the fact that within 10 -20 years of exploitation it will not require large financial expenditures (providing that necessary surface maintenance is carried out). In asphalt structures, milling of the wear off layer is already necessary after 6-7 years [5 -15]. This leads to the question: which technology to choose, which one is better?

Comparative analyses of road building technologies -Hellwig's method
The article presents the comparative analyses of two road building technologies, an asphalt one and a concrete one. It is assumed that all variables: technological-technical -usable ones, statistically are of the same importance and can positively or negatively influence the choice of road pavement technology. For the calculations, Hellwig's modified synthetic meter of development was used [27,28]. In accordance with Table 1 and Table 2, the divisions and features important for the choice of road building technology were determined and Euclidean distances for features in divisions were calculated as well as meters for individual divisions and synthetic meters for both technologies . Five groups -thematic divisions were determined (table 1). Where: And: The standardization of features (Table 3) was the introductory phase which enables obtaining total multi-criteria assessment of each considered division Measure M1 takes a value from the interval [0;1]. The nearer a given object is to the model, the higher these values are.

Summary
When choosing a road building technology one cannot be limited to building costs alone, but it is necessary to also consider the costs of maintenance and exploitation some 30-40 years later. The main purpose when choosing the road building technology is to build the roads of such a quality that would enable their long time exploitation and usage. Based on the analyses made with the use of the Hellwig method, it is possible to state that both technologies, the asphalt one and the concrete one can be competitive since it leads to their progress and development. Considering the growth of traffic on the roads, concrete can be perceived as a technical and economic alternative to asphalt structures, which is confirmed by presented analyses.