In year 2004 we acquired and carried out commission of weighing traffic on several locations throughout Slovenia (picture 1). We were seeking out for suitable locations (30 bridges or culverts) where we took measurements. In recent years we performed 20 measurements in year2002 and 20 measurements in year 2003.

Basic criteria , on which we estimate adequacy of bridge (measuring ground):

On several recommended road sections there were not adequate structures for conductingweigh-in-motion with bridge SiWIM system. When a suitable structure was not obtainable (poor road condition, un-adequate construction) we agreed with our commissioner that, in pursuit of accurate results, we make measurements on adjoining road section.

We acquired data as follows:

average daily FE acquired on locations - legal loadings (green colour) and those overloaded (red colour)

Our data was created with the formula shown bellow. In accordance with technical specifications for traffic overloading calculations TSC 06.511 is vehicle influence on road constructions with equivalence factor FE which determines no. of nominal axe crossing with two-double pneumatics and axles burdening equal to 82kN, same as:

Legend:

FE - traffic loading expressed with no. of nominal axe loadings 82 kN

f₀ - burdening factor on typeof axe (2,212 for single axles; 0,0195 for double axles and 0,0048 for triple axles)

f_k - type of wheel factor (1,0 for double tires; 1,2 for wide base single tires and 1,3 for single tires)

A_i - burdening of single axe in kN

N - no. of axes

Results that are shown are leading to a suggestion that we can prevent road damaging and collect more fines.

For conducting traffic surveillance and penalization of violators in Slovenia we need 40 constant WIM systems. That financially means somewhere around SIT 250 million per annum for acquisiton, maintenance, calibration and data processing. That is sixty times less than collected penalties. There are also some other benefits:

    - slower dilapidation of roads and lower maintenance costs

    - better traffic safety

    - higher driving comfort

    - lower enviromental effects