We have used the PID quite a few times since we got the car last year, today it announced a traffic warning in 25 miles and came up on screen in a red box 3 cars behind each other. 25 miles down the road and a queue of traffic, is this a new update or have I pressed a button which I have not touched before?.

It's the TMC traffic reporting system. If you press the queuing traffic icon, you get details of the delay iirc.

The Garmin PID will either get traffic updates via the radio using TMC (don't ask me what it stands for), or it will get live traffic updates via a smartphone's data connection when you link a smartphone to the PID using bluetooth.

The icon pops up to warn of delays en-route if you navigate a route or, if you just select map view on the home navigation screen, any delays nearby: I use this to warn me of delays nearby when I am home and don't need to navigate.

It's the TMC traffic reporting system. If you press the queuing traffic icon, you get details of the delay iirc.

This, mine also says "A new traffic alert is on your route" and then 9 times out of 10 it will say "there is no recommended alternative route" thanks SatNav if there is an alternative route it'll ask you if you wish to take the new route 

Edited 10 May, 201610 yr by Hyphons

My traffic updates don't work via radio, and I don't use data for the internet based traffic updates...

Will it be affected because i live on the coast?