It had to be too good to last. A few times in the past couple of weeks the 508’s traffic alert system has helped me avoid major queues, meaning I’ve avoided the frustration of sitting helpless for half-an-hour or so while waiting for a problem to clear.

Each time the warnings - which pop up on the car’s sat-nav screen and inform you of incidents on major roads nearby, where the problem is, what direction it is in, and how long the hold-up is – have given me time to find alternative routes.

This has been easy as the 508’s sat-nav screen is a generous size, prominently placed, and the mapping is excellent.

And it has made me feel rather smug that I’ve been able to keep moving, having outsmarted other vehicles.

But last week it made me feel a bit silly. Not because it had misinformed me, or done anything wrong – far from it.

In its usually efficient way, the 508’s traffic alerts told me about an incident on the main road I was minutes away from joining. The congestion wasn’t on my route, so that wasn’t a problem.

Where my embarrassment stems from is that in the alert’s top line where it usually says something along the lines of “slow traffic for 4.5 miles”, it simply said: “Shed load.”

Now, the only thought in my mind was that whoever issues the traffic alerts wasn’t sure how much congestion there was, so instead of giving a precise amount, it used a slang term meaning a lot.

This made me smile so I couldn’t understand why, when I was telling my colleagues about this later, that I was getting looked at as if I was one sandwich short of a picnic.

It slowly dawned on me that it was probably referring to the jam being caused by a vehicle which had shed its load – a thought confirmed by a story on my local newspaper’s website later in the day.

Otherwise - my my own foolishness excluded - the 508 has continued to impress. It offers an enjoyable driving experience, a comfortable ride, and combines strong performance with excellent fuel economy.

In my last report I stated my aim of travelling 900 miles on a single tank of diesel after coming close a couple of times. This was achieved with 912.6 miles, with the trip computer indicating I had another 55 miles to go before empty.

A quick calculation showed this was an average of 58.6mpg over the tank – slightly better than the official combined economy of 56.2mpg.

Unfortunately the minor glitch where the trip computer freezes, reporting an overall fuel economy of 999mpg, has returned, but this tiny irritant hasn’t spoiled what has been a very impressive experience with the 508.