Paul Johnson <[email protected]> writes: > On Fri, Dec 7, 2018, 09:27 Greg Troxel <[email protected] wrote: > >> Paul Johnson <[email protected]> writes: >> >> I see maxspeed:typical as being for the flow of mixed traffic that is >> being reasonable. > > Not sure this is a tag we even need in this case, since it can be inferred > automatically from the GPX database.
I have been thinking of getting around to matching up GPX and OSM, but more to add advisory/practical when it's out of whack with limits. But perhaps the map building process could extract that. I gather that apple maps use the equivalent of real-time gpx from others to inform routing. >> However, my specific example is a ramp where the advisory signs say 20 >> mph but traffic is 99% of the time moving between 35mph (if there's a >> cautious truck) and 50 mph (just cars, people familiar). The 20 signs >> are because trucks going >50 keep rolling over, I think - which does not >> make sense. >> > > Keep in mind in the US and Canada, the advisory speeds are meant for > average family cars, trucks are advised to go slower. Not saying that it's > not always feasible to go faster than that, but it is the speed you're > going to be able to traverse that section in a regular car on dry pavement > without having to make abrupt moves or brake hard either due to the design > of the road or typical traffic congestion. That said, Americans are > aggressive drivers that typically take a much more aggressive approach > than they're advised to, esp. in familiar areas... That is the theory, and I agree with it. I sort of see it as "what speed can you travel the ramp and not exceed 0.4g lateral" or something like that. Under that theory, the ramp in question would be 40, not 20, and the other one would be 30 or even 25, not 35. They are just signed not using the guidelines. > The tippy truck signs indicate to large vehicle drivers that they will need > to play on the side of extra caution because the location has been prone to > rollovers, the advised speed is still tuned to cars, however. In theory it is tuned to cars. It seems in this case that the trucks kept tipping, and every crash - despite the trucks going clearly too fast - they added more tippy truck signs and lowered the advisory speed. So it's more like "if we post it 20 trucks might slow down to 40" in this case. Which leads to MA drivers not believing that the advisory speeds are appropriate. -- You received this message because you are subscribed to the Google Groups "Osmand" group. To unsubscribe from this group and stop receiving emails from it, send an email to [email protected]. For more options, visit https://groups.google.com/d/optout.
