Before 4.5 I could refresh the traffic indicators in Google Maps by tapping on another app and then tapping back on the Nav app -- which would cause the entire map, including traffic, to refresh. Now the map and traffic data seem to be cached, which makes them display very quickly, but I can't find any way to cause the traffic indicators to refresh. Since I commute about an hour each way every day it's generally true that the traffic patterns change during my commute, but I can't figure out to get the traffic to update. This unfortunately makes the traffic feature pretty much useless to me. Any suggestions?