I've read several threads on here about the navigation system and how bad it is... but no one has any inputs as to why the time to destination is always so high. For example, last weekend I was driving from Houston, TX to Carbon, TX to do a little deer hunting in my TL and the route guidance was horrible.

I just checked the nav from my driveway to the ranch and it's suggested route is to take I45 to Dallas and I20 west towards Carbon at a time of 6 hours 53 minutes for 242 miles. That would be 35.17 mph. Google maps is about the same but suggests about 6 hours drive time. The route I actually drove took about 4.5 hours taking Highway 6 from College Station. The nav says this route should take 8 hours and 8 minutes for 288 miles. That's 36 mph. Anyone who has driven these roads knows that's almost impossible to go that slow.

I'd be better served to take the miles and divide by 65 mph to get an accurate time to destination. The garmin I used to have was very accurate on time and displayed it at time of arrival instead of time to destination.

So three questions... :
Has anyone else noticed the nav time to destination being completely off?
Can the nav be adjusted to output time of arrival instead of time to destination?
Can the nav be adjusted/updated on average speeds?

 

I have noticed my projected drive times being a little pessimistic, to the point that I've noticed that a recommended route that projects 1.5 hours drive time might just take 62 minutes.

I haven't noticed anything quite as bad as what you're saying, but then I haven't gone on any six or seven hour drives, yet!!

 

Calculate the mat on this one


I find the Nav system will both over and under estimates times. When I go on longer trips, to areas I don't know, it's usually very accurate.

 

I've also noticed that the nav system in my TL sometimes over estimates the time needed to reach a destination. The nav system I had in my Lexus seemed more accurate and would adjust for changing driving speeds.

Does something need to be adjusted to make it more accurate?

 

You know...funny how this thread came up...

When I first got my TL, a drive to Baltimore from College Park, MD was about an hour. This time is pretty legitimate for 35-40 miles though. After 7 months, I noticed if I put in the same time, it would be 35 mins. This carried over to everything that was around the same mileage range so I think the car does adjust based on habitual driving speed. It doesn't seem to change based on current speed, but over time it does.

 

I always arrive sooner then the indicated time from the navi. The only time I arrive afterwards is when I deal with traffic. I don't have real-time traffic service.

 

bumping this old thread..how do you get rid of the 'time to destination' message into 'estimated time off arrrival'? I hope there is a way to do this...every other car I have driven with Nav has this very important feature and so does every $100 garmin!!

Please help..

 

I notice that in my area, it doesn't take into account the city's unsynced and loong ass stop lights...so it always underestimates the time...

 

Even considering. I'd have to be going anywhere from 72 to 144 mph to get 2.4 miles in 60 to 119 seconds.