Florian Lohoff wrote:
Wouldnt it make sense to make it possible to apply factors based on road class to the maxspeed setting?
e.g unclassified -> maxspeed*0.6 tertiary -> maxspeed*0.8
OTOH this should all be the responsibility of the routing engine and at the moment as i understand we abuse the maxspeed (OSM) to set an "average speed" in the Garmin dataset - not something like a speed limit which is obviously broken anyway and just some idea to make use of the maxspeed ...
I'd come across this whilst setting up the patch. The main road near me has maxspeed=50mph on it. This then gets converted to kilometers and just scrapes over the 80kph barrier and gets a road class of 5 which effectively assumes you will never drop below the speed limit. My feeling was that there might be a case for another patch which reduces the maxspeed by a certain amount (eg. 5mph or by 20%) when deciding which road class to allocate. This probably needs (yet) another parameter. My patch isn't really concerned with how the maxspeed tag is converted to a road class. It is aimed at deciding whether to use set the road class from the style file, the maxspeed tag (however that is translated to road class) or both.