Missing prompt when joining major road from minor road at an angle
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Does the IMG file contain markup on junctions to control whether or not a "turn left/right" announcement will occur when you reach it? I've got a case locally where a tertiary road meets a primary road at a shallow approach-angle of about 30 degrees. The Garmin does not announce the junction, not warn of its approach when you're on the tertiary. Coming from the other direction on the primary though, you get an "in 500m, keep right" announcement followed by "keep right" when you're almost at the junction. It would be good to be told to "turn left" when approaching on the tertiary. I can quite understand that if you're approaching a motorway on a motorway_link type of road, then you don't need to be told to join the actual motorway when you get to the merge-point. I wonder if the code that avoids causing an announcement in that case is a bit too eager and does the same for my tertiary-meets-primary situation? Steve
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I've got a case locally where a tertiary road meets a primary road at a shallow approach-angle of about 30 degrees. The Garmin does not announce the junction, not warn of its approach when you're on the tertiary. Coming from the other direction on the primary though, you get an "in 500m, keep right" announcement followed by "keep right" when you're almost at the junction. I have seen this with garmin's proprietary maps.
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Greg Troxel wrote:
I've got a case locally where a tertiary road meets a primary road at a shallow approach-angle of about 30 degrees. The Garmin does not announce the junction [...]
I have seen this with garmin's proprietary maps.
Ah - so it's Garmin's announcement-engine that makes the decision is it? OK. I have a request. ( There may be code floating about which will implement this without too much heartache too... ) Could mkgmap examine junctions between roads of different class, find the angle-of-approach (AOA), and if AOA < some magic number (maybe 30 degrees) then slip an extra node into the more minor road just by the junction so as to make the junction itself happen at 90 degrees? I ask this because in addition to getting missing warnings on some junctions, I also get quite a few bogus "keep left/right" instructions where a minor road (sometimes just a farm track) meets the more major road at a narrow angle, but it's obvious to any driver that you don't deviate from the more obvious road unless instructed to do so. Some code like this was tried back in about April as an attempt to improve the driving instructions on roundabouts, and maybe motorway exits. That code might be re-usable here. I'd suggest avoiding doing the AOA fiddling described above if the "minor" road is an XXX_link and the "major" road is an XXX, BTW. Steve
participants (2)
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Greg Troxel
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Steve Hosgood