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planning is using too high of a speed, speed limit data seems to be missing

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Description: Planning a route from NE Florida to Wilmington, NC.  It keeps routing me through Charleston and Myrtle Beach which would be much slower than travelling Northbound on I-95 all the way to US74 near Lumberton NC then East from there.  But the resulting times don't align with what I see using google maps to plan the route.  There would be lots of stoplights, slow speed zones, etc. along this route and I was puzzled, until I clicked on the route line in a random location and see speeds such as 71MPH planned through Litchfield Beach, where it seems the speed limit is 45MPH.
I clicked on the Open street map thing to edit it, and I tried to add speed limits to a few sections, but this is beyond my capability.
Type: web based planner
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thanks... but no, definitely not metric.

when I click on the road segment it shows a box

some sort of elevation graph

says speed 71MPH in bold at the top

and below the graph it says speed limit unknown

and when I looked at openstreetmap there was no limit listed for the segment.

Then I went to google street view and confirmed speed limit signs 45MPH


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71mph might be the planned speed here then (which ABRP expects you to drive at this point to estimate consumption). If speed limit is unknown it might take the upper limit of those kind of streets for your country.

If osm does not have the correct data we have to guess, so there is not much we can do about this. It is pretty easy to adjust the speed limits on OSM, I did it a few times already. Normally you just click on the road and add the maxspeed property with the speed limit. You can also ask people to review your changes before they go live in case you are not sure that you did it right.

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yes, as I said initially I discovered that's it's possible....and tried doing it to help ABRP's results, but I found it very glitchy on my computer...and tedious doing one short little road segment at a time.  Interesting...just before seeing your reply I tried it again this morning.  There's probably a way to select longer stretches of the route to be more efficient but it's not obvious to me.  Also I suppose it's probably easier with a larger monitor and proper mouse which I don't have at the moment.

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for whatever it's worth... IF i did it correctly.....I went in this morning and added speed limits to all the road segments from the bridge at Georgetown SC North up to the Southern ends of Myrtle Beach, SC

It looks like there are a lot more areas along this route with unknown speed limits, but it's a start!

How long does it take to synchronize the data over?

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what do you mean "if that did not change recently?

I'm new to the Open Street Map editing...but it seems like my edits pretty much go live immediately.  If that's true, which I'm not sure that it is, then it seems like it would depend on how often ABRP synchronizes to OSM.  Is it a rolling thing by region, or set on some timer...every so many days, etc.?

Over the last few days I have been adding some speed limits to OSM for some of these areas.  I have been focusing on some of these off interstate highway routes that ABRP is suggestion for my upcoming trip.  Lots of little towns with 35MPH zones where your plan has me going 71MPH, etc...  I have been going segment by segment, looking at Google street view to find speed limit signs.  Probably not perfectly up to date but certainly better than nothing.  I haven't been able to do do the complete route but have covered some fairly long stretches

Side note, I don't understand where 71 MPH comes from.  I have plugged in I think 115% of the speed limit with a max speed of either 80 or 85 MPH.  Why would the plan have me go 71?

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I have a suggestion.

On the planned route, the path is highlighted Blue.

I think it could be useful to highlight the line different colors...such as pink could be "missing speed limit data".  That way, at first glance a person can spot areas where the plan might be falling very far from what they will get.

+ it might help to encourage crowd sourcing in Open Street Map to fix the unknowns.

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