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The article claims that the "match roads by turns" technique "was later adopted by all navigation apps". Does anyone know if this is true? My impression was tha

The article claims that the "match roads by turns" technique "was later adopted by all navigation apps". Does anyone know if this is true? My impression was that they rely on GPS position only for positioning, even though modern phone hardware should give really nice gyroscope/accelerometer data.

LeoPanthera 3y ago
Virtually all car navigation software, or phone GPS apps in driving mode, will "snap" to a nearby road if the GPS indicates that you are traveling parallel to one. This compensates for minor GPS reception errors. This can occasionally, in rare situations, be a problem, if you have frontage roads very close to a highway, they can sometimes get confused about which road you are actually on.
- guenthert 3y ago
  In car navigation software it's not all that rare. Chances are the maps are out of date, perhaps by quite a few years (because manufacturers ask for absurd prices on map updates) and you're traveling on a road which doesn't yet exist on the map ...
- hoseja 3y ago
  It LOVES to happen on complicated in-construction off-grade intersections, where you usually need the navigation the most.
- mauvehaus 3y ago
  I love when I've been traveling at highway speed down a highway for over an hour, and suddenly my GPS starts giving me directions back to the highway from some nearby parallel road when I haven't so much as passed an exit.
- myself248 3y ago
  It's incessant for me; a significant part of one of my frequent routes is on the service-drive that parallels a major freeway, after taking an exit, but prior to diverging. Depending on traffic, though, it may also be advantageous to stay on the freeway, so both are valid parts of the route. If Waze instructs me to take the exit, then it assumes I'm on the service drive, even if GPS says I'm still on the freeway. And vice-versa, more problematically -- if I impulsively take the exit, it assumes I'm still on the freeway even if GPS clearly shows I'm on the service drive. (I can confirm this by running a spare laptop with a USB GPS as a logger, while my iPhone runs Waze. Overlay the GPX on a map later and it's super obvious whether I took the exit or not, but either the Apple location provider or Waze staunchly ignores reality in favor of obsessive road snapping.) Where this gets stupid is, if there's a traffic jam on the freeway and I dip onto the exit to avoid it, now Waze sees me flowing freely down the service drive, assumes that it's the freeway that's flowing freely, and disbelieves other users who report traffic there. Even as the service drive curves and diverges and I follow the curve, it doesn't retroactively say "Oh jeez, he must be on the service drive after all, adjust the previous data to apply to the service drive and not to the freeway!". So the bad data continues to corrupt the traffic picture and encourage other users to get stuck in traffic they can't report.
mariusor 3y ago
I interpreted that to mean that any error in GPS coordinates will be snapped to the closest road that matches the direction vector. (At the same time, I doubt my understanding since I've seen plenty of navigation systems show the vehicle not on the road when traveling on less well covered GPS areas).
incorrecthorse 3y ago
Most modern navigation apps continue working in tunnels and other places without GPS. It's more like GPS augmented with dead reckoning.
- tgsovlerkhgsel 3y ago
  Is that sensor based dead reckoning or simple interpolation based on the previous (or expected) speed of travel along the route though?
Cthulhu_ 3y ago
GPS and other signals aren't continuous, they all use dead reckoning to fill in the blanks in between. This was even more of a necessity with early smartphones and navigation systems that only had GPS; nowadays they can use a combination of GPS, GSS, Gallileo, GPS and wifi networks. The latter was a secondary goal of the Google Street View project, matching GPS / location with wifi signals.
- BenjiWiebe 3y ago
  Your list should be: GPS, Galileo, BeiDou, GLONASS, and Wifi. Probably cellular too.
stavros 3y ago
When nearing a turn you're supposed to take, try stopping completely and rotating your phone as if you're in the turn. Google Maps will continue into the turn before correcting back to the place you stopped. It doesn't do this if you don't rotate the phone.
AshamedCaptain 3y ago
Try googling GPS "Lock on Road" for some examples.

LeoPanthera 3y ago

Virtually all car navigation software, or phone GPS apps in driving mode, will "snap" to a nearby road if the GPS indicates that you are traveling parallel to one. This compensates for minor GPS reception errors. This can occasionally, in rare situations, be a problem, if you have frontage roads very close to a highway, they can sometimes get confused about which road you are actually on.

guenthert 3y ago
In car navigation software it's not all that rare. Chances are the maps are out of date, perhaps by quite a few years (because manufacturers ask for absurd prices on map updates) and you're traveling on a road which doesn't yet exist on the map ...
hoseja 3y ago
It LOVES to happen on complicated in-construction off-grade intersections, where you usually need the navigation the most.
mauvehaus 3y ago
I love when I've been traveling at highway speed down a highway for over an hour, and suddenly my GPS starts giving me directions back to the highway from some nearby parallel road when I haven't so much as passed an exit.
myself248 3y ago
It's incessant for me; a significant part of one of my frequent routes is on the service-drive that parallels a major freeway, after taking an exit, but prior to diverging. Depending on traffic, though, it may also be advantageous to stay on the freeway, so both are valid parts of the route. If Waze instructs me to take the exit, then it assumes I'm on the service drive, even if GPS says I'm still on the freeway. And vice-versa, more problematically -- if I impulsively take the exit, it assumes I'm still on the freeway even if GPS clearly shows I'm on the service drive. (I can confirm this by running a spare laptop with a USB GPS as a logger, while my iPhone runs Waze. Overlay the GPX on a map later and it's super obvious whether I took the exit or not, but either the Apple location provider or Waze staunchly ignores reality in favor of obsessive road snapping.) Where this gets stupid is, if there's a traffic jam on the freeway and I dip onto the exit to avoid it, now Waze sees me flowing freely down the service drive, assumes that it's the freeway that's flowing freely, and disbelieves other users who report traffic there. Even as the service drive curves and diverges and I follow the curve, it doesn't retroactively say "Oh jeez, he must be on the service drive after all, adjust the previous data to apply to the service drive and not to the freeway!". So the bad data continues to corrupt the traffic picture and encourage other users to get stuck in traffic they can't report.

mariusor 3y ago

I interpreted that to mean that any error in GPS coordinates will be snapped to the closest road that matches the direction vector. (At the same time, I doubt my understanding since I've seen plenty of navigation systems show the vehicle not on the road when traveling on less well covered GPS areas).

incorrecthorse 3y ago

Most modern navigation apps continue working in tunnels and other places without GPS. It's more like GPS augmented with dead reckoning.

tgsovlerkhgsel 3y ago
Is that sensor based dead reckoning or simple interpolation based on the previous (or expected) speed of travel along the route though?

Cthulhu_ 3y ago

GPS and other signals aren't continuous, they all use dead reckoning to fill in the blanks in between. This was even more of a necessity with early smartphones and navigation systems that only had GPS; nowadays they can use a combination of GPS, GSS, Gallileo, GPS and wifi networks. The latter was a secondary goal of the Google Street View project, matching GPS / location with wifi signals.

BenjiWiebe 3y ago
Your list should be: GPS, Galileo, BeiDou, GLONASS, and Wifi. Probably cellular too.

stavros 3y ago

When nearing a turn you're supposed to take, try stopping completely and rotating your phone as if you're in the turn. Google Maps will continue into the turn before correcting back to the place you stopped. It doesn't do this if you don't rotate the phone.

AshamedCaptain 3y ago

Try googling GPS "Lock on Road" for some examples.