Garmin C530 sometimes will not show up the shortest navigation

Could you explain what you mean? Are you saying that your menu choice isn't available (fast time / short route) or the unit is routing incorrectly?

Could you give an example of a route you are trying to make?

Daniel

dkeane, thx for your quick response. My c530 is set to shortest route. It routed incorrectly sometimes. For example, one of the shortest route is making left turn then keep going on road A south (road A is on the map) 1 mile to arrive the destination. But the unit will tell turn right on road A north then turn left on road B, then turn left on road C, make an extra 5 miles circle route to reach the same destination. I hope this is not too confused to you.

It is possible that the Road A was at one time a one way. My suggestion is to pick a point part way on Road A and then navigate to that point to see if this is true. Another possibility is that Road A is a toll road and you have avoidances set for tolls roads.

You will notice that at times your unit will "send you around the block" to make a turn as you describe. In some places it avoids left turns at all costs. That is why I will try and make sure that I touch the top of the screen and then view map to look at the whole route or tough the right corner to check the directions. I don't always follow blindly....

It is the same way on my c580, but I don't notice it very often.

Daniel

Here are two tests I have made:
1. I picked up one location on Road A. It showed up correct route and told me turn left.

2. Even the unit told me turn right to Road A north, I didn't follow it just made a left turn. Then it made recalculating and correcting the route to Road A south within a minute.

I checked my unit settings that the avoidance is disabled and the road A is standard freeway. Just confused.

dkeane, you're right. Can't trust it all the time. Better to view the whole route before drive down the road.

Two more things: There is a road in my subdivision had been finished five years but couldn't find on Garmin's map. There is a school built three years ago not in Garmin map database either. Furthermore sometimes a destination address can show up on the Garmin's Map if I am browsing the unit map and use finger point the right street. For example, 1709 Time Saver Drive. I am browsing the unit map and locate the street, then use finger point it, it comes up 1701 Time Saver Drive, then I point next to it, will show up 1702 Time Saver Drive. But if you use "where to" to type the same address, it will tell you "no match address found".

wouldnt it be nice if we can add our own roads in map source