Point-based estimation of calculated speed profiles for road segments

Route planning for freight and personal navigation in urban areas is rather difficult because optimal route is not only distance-but also time-dependent. This task often depends on varying traffic conditions which can be influenced by different factors. Optimal route planning is therefore dependent on the time of the day and of the day in the week for different urban areas. One of the usual solutions to this problem is calculation of speed profiles from GPS traces gathered from different vehicles. Speed profiles are calculated estimates of average speed which can be achieved on a specific road segment during one day. To calculate speed profiles we used gathered GPS data collected during five years and 4,000 vehicles, mostly in urban areas in Croatia. There are different approaches considering time and distance averaging, and final results depend of the chosen values. Actual speed estimation can be made using radar measurements which are point-based but can give a good estimate for the chosen segment. In this paper we compare measurements obtained using Frequency Modulated Continuous Wave (FMCW) radars with calculated speed profiles and present difference for the four road segments.