When is map traffic data updated?

keep us posted on this ...

last night on my way back to work I saw that there was a big slowdown on the stretch of 101 near where I work. I checked my map mode in google maps and it had the colours right perfectly for the stretch where the slowdown was.

How do they collect this data anyway?

Google maps gets their data from services in each metropolitan area. So, there are at least 3 layers of updating going on. The data service gets updated through sensors on the freeways and roads. Google updates their graphic overlays. Then the last step is the phone getting the update. I am not sure if things cache or how often it refreshes on the phone, but the Edge network that you were probably on takes a while to update. Also, yesterday (still?) the Edge network was having "issues" on the west coast (and midwest?). So, many things can account for this. I think over time the community will begin to understand how reliable this is.

Another thing is that ATT might be doing a lot of caching on the servers that operate the Edge services. So, they may be caching to increase performance at the cost of being less "real-time".

A way to check how the phone work in this regard is to turn off wireless on the phone while at your computer and use google maps on the computer at the same time and see if the data represented is the same. Should be. If not, the phone either has caching issues or Edge network issues.

I've noticed the same thing about the traffic data in Chicago--sometimes I'll get out of date information. I've had this happen both over WiFi and EDGE, so I think that the caching is mostly happening on the phone itself. I haven't found a way to force a refresh other than by loading some other page and then coming back to my original page. Which can be a pain while sitting at a red light trying to get info on which road to take to work before the light turns green!

Don't get me wrong, the traffic feature alone is almost worth the price of the phone to me, but I wish there was a simple-to-access "refresh" button for the traffic. Something as simple as hitting the traffic button again would work fine for me.

17 PowerBook (Rev A) Mac OS X (10.4.10)

I am having this same problem, but I think my husband and I figured it out.

About 11:30am today, I checked traffic in the Los Angeles area and it was red all over. I panicked and called some business associates to let them know we were in for a bumper to bumper ride to our meeting. It turns out that the traffic moved at or above speed limit the whole way.

I looked at my traffic map on my iPhone again around 4pm and the traffic was exactly the same as it was at 11:30am (very red).

When I got home tonight I mentioned it to my husband. We did a little investigation and found that the problem is on Google's end. Shortly before posting this, we went to maps.google.com and the traffic was exactly as it was reported on my iPhone. My husband also checked it on his Blackberry and it was the same as on my iPhone and on Google's website. Then we went to sigalert.com, the map was all green.

So - it's our guess that Google sometimes has glitches in their reporting. The traffic report that they have on their site right now is probably from this morning's rush hour commute. I hope they resolve it soon. That's a critical feature for me.