Modified speed factors

To try and best estimate an average travel speed where other speed information is not included in the dataset, the HERE GIS Data Suite applies speed factors based on the values of URBAN and CONDITIONAL_ACCESS for a link to SPEED_KPH. The table below illustrates the factors used, for example for a conditional access road in an urban area the estimate for the average speed along the link is 80% of SPEED_KPH. One way links cause application of an incorrect factor and reduction of the traversal speed by half, which doubles the traversal time for emergency vehicles. These vehicles' drivers may choose to travel against oneway restrictions in some cases. These factors are part of the calculation of TO_FROM_MOD_SPEEDKPH_MINUTES on routing_streets, which is in turn part of the calculation of the Mod_Time (Mod_Time_Using_SpeedKPH) network cost.

Conditional Access / Urban	Y	N
Y	80%	62%
N	95%	85%