AndyPoms wrote:If it's just a lane and not a separate road, the GPS system (not Waze, but the actual GPS system) doesn't have the resolution to know which lane you are in, so it won't be able to tell if you are in the HOV lane or not.
james9becker wrote:In response to CBenson's comments, another place where there are speed differences is at stop lights where the wait time is dependent on the direction taken after the light. It becomes even more fun when this intersection is at a freeway exit. Then there can be a multitude of potential directions. With different signal timing and right turn on red.
I looked it all up & I cited my sources (the little numbers in parentheses).jwriddle wrote:AndyPoms wrote:The lane guidance in other GPS units is done essentially by segment - it doesn't actually know what lane you are in, but information about the number lanes on the segment you are on.
Besides at a 95% confidence level, civilian GPS is only accurate to 7.8 meters (just over 25 feet)(1) - and minimum lane width in the US is 12 feet (2) so 25 feet covers two full lanes on either side.
You're a walking Wiki of stats.
I agree that's the likely case. The client has to operate on the assumption you're following its directions as accuracy isn't yet high enough across all platforms to conclusively determine you've actually deviated two lanes width without a lot of false positives.sketch wrote:This will probably affect the "current traffic" speed, yes, but it shouldn't affect historical data, provided that the GPS traces are accurate enough. That's done with later analysis once your drives are uploaded.
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