Complex sentence: The D528 state road traffic volume is not reported by Hrvatske ceste, however they regularly count and report traffic volume on the A4 motorway Varaždin interchange, which connects to the D528 road only, thus permitting the D528 road traffic volume to be accurately calculated.
Split into simpler sentences: The D528 state road traffic volume is not reported by Hrvatske ceste. However, they regularly count and report traffic volume on the A4 motorway Varaždin interchange, which connects to the D528 road only, thus permitting the D528 road traffic volume to be accurately calculated.