ETA on Route Advisor Inaccurate?

[n4gix]

I'm not certain when this appeared. It's entirely possible it's always been this way and I just never noticed it before...

At any rate, as can be clearly seen in this cropped screenshot of the Route Advisor, I'm tooling along at 65 mph (~110 kph), the remaining distance is 82 miles, but the Route Advisor is calculating just slightly over 2 hours remaining!

TripAdvisor_Error_01.png (209.37 KiB) Viewed 8143 times

In addition, although I don't have a screenshot of it, on another trip I had 484 liters fuel remaining, yet the Route Advisor was informing me I was "low on fuel" and suggested that I fill up soon. My Scania has 1400 liter capacity, so 484 liters remaining is certainly not "too low..."

[ohaha]

The route is computed at 62 kph, regardless of your current speed.

[n4gix]

The route is computed at 62 kph, regardless of your current speed.

While that might well be the top limit, I have noticed that if you maintain 30 kph for several minutes, the ETA is recalculated to reflect that average speed.

In any case, with the new selectable option to disable the speed limiter, it might be a good idea to revise the ETA calculation to work with higher average speeds.

[ohaha]

Are you sure? Because there is a parameter, in game_data.sii, I think, that can be set to whatever, but I haven't seen the eta being dynamically adjusted...
and, if we're on the subject, the realistic way to calculate it is based on the local speed limit, for each section of road, not on your driving speed. at least, that's how all gps programs do it.

[Flemming V]

If you drive a different way than calculated, the RA recalculates the job on every road segment.
As Ohaha says it calc. the speed to around 62km/h as I remember.

[n4gix]

...the realistic way to calculate it is based on the local speed limit, for each section of road, not on your driving speed. at least, that's how all gps programs do it.

My Garmin Nuvi calculates my ETA based on my actual driving speed, which makes perfect sense because I might just be driving like a "Little Old Lady" if I'm just out for a pleasure drive...

Oddly enough, the actual speed displayed on my Nuvi is more accurate than the mechanical speedometer in my old Mercury Grand Marquis LS.

[Flemming V]

Yes, the GPS is almost always more accurate than the speedometer in cars.

[ohaha]

...the realistic way to calculate it is based on the local speed limit, for each section of road, not on your driving speed. at least, that's how all gps programs do it.

My Garmin Nuvi calculates my ETA based on my actual driving speed, which makes perfect sense because I might just be driving like a "Little Old Lady" if I'm just out for a pleasure drive...

Oddly enough, the actual speed displayed on my Nuvi is more accurate than the mechanical speedometer in my old Mercury Grand Marquis LS.

Never liked Garmin I have only used devices based on WinCE, on which I can install my own software (usually iGo). Regarding the estimation based on current speed, what happens if you stop at a traffic light?

The GPS displayed speed is the most accurate, so it should be odd. The one on your dashboard is affected by a lot of factors, from the size of the tires mounted on your car (if they are bigger, the car shows less) to the wear of the mechanisms involved in displaying the info. My car shows an average of 4 kph more than the GPS, but this difference increases with the speed, to almost 10 kph, when I hit ~ 130 kph.

[Unco]

My car shows an average of 4 kph more than the GPS, but this difference increases with the speed, to almost 10 kph, when I hit ~ 130 kph.

Manufacturers do that on purpose, by law.

[ohaha]

My car shows an average of 4 kph more than the GPS, but this difference increases with the speed, to almost 10 kph, when I hit ~ 130 kph.

Manufacturers do that on purpose, by law.

Law or not, I know they do it.
Actually, I have two allowed tire sizes for my car. I had the small ones until recently and the difference was around 8 kph, at normal city speed. I'm glad I got rid of them