0> In article <212454.24051.qm@web28515.mail.ukl.yahoo.com>, 0> Marco Certelli <URL:mailto:marco_certelli@yahoo.it> ("Marco") wrote: Marco> 1st: I do not know very well how to keep the answer in the same Marco> thread... Just follow-up in the normal way (sometimes called "group reply" or "reply to all"), then remove the original sender from the recipients (so that you don't annoy them by sending two copies). Marco> I can speed on a city road at 60 km/h during night and 15 km/h Marco> during day. ... And of course I can just imagine the endless Marco> discussions for each road about the right value to give to an Marco> "average_speed" tag... Much better would be to automatically Marco> calculate an average_speed tag by using all information the OSM Marco> DB already have: the highway type, the maxspeed tag, the number Marco> of crosses per kilometer, the curves (radius and frequency) and Marco> also the available GPX real speed data. Yes - IIRC there is a Summer of Code project to collect and use gathered speed data from GPS tracks to give realistic speed estimates. But the Garmin maps don't (as far as we know!) have any provision for time-dependent speeds. So it's always going to be a very rough estimate. Let's not get too worked up about these details yet!