Day 4 of our Sardinian west-coast tour from Riola Sardo to Guspini was a pleasant, flat ride along back roads with a final gentle climb into Guspini.  

Day 5 from Guspini to Cagliari was another matter.  Most of the route was fine (a detour 3.5 km in [via point 1] because of a closed back road, and something of a lottery as to whether a section marked as paved was actually unpaved, and vice-versa were minor suprises that added some acceptable adventure to the day).  

But the final 5 km along the alleged Sardinian cycle route (marked CS13 on cycle.travel) is no longer passable, and required a major detour.  

4 km after Assemeni we hit the signposted cycleway. There were no signs indicating a closure. The first partial barrier is a small, partly collapsed footbridge (via point 2). We risked wheeling our bikes across this, and it was ok. However, another few hundred metres brought us to a larger bridge across the Riu de Sestu (via point 3, see photo), which has been burnt down, and is totally impassable.

Nevertheless, we persisted and back-tracked to the start of the cycleway and crossed the railway line to follow the bike paths of Elmas across the head of the Riu de Sestu and found our way to the cycleway on other side of the burnt-out bridge. It was an adequate unpaved and paved road for 4 km past the airport until we reached Via Girolamo Emiliani (viapoint 4) where the track drops down to the railway line. And there we found that Trenitalia have closed and fenced off the trail, making it completely impassable.

With an hour and a half before we needed to board the weekly ferry from Cagliari we had no other option but to brave the insane network of autostrada that are the only other entree into Cagliari from this point. It was a heart-in-the-mouth 15-km detour through some confusing clover-leaf intersections before we found our way onto the port exit that left us with a couple of km of not-so busy roads to the port. A great relief!

cycle.travel sensibly does not permit you to plot a route along those autostrade. But we had no choice. If we had more time (and hadn't been held up by a flat tyre earlier in the day), we would have ridden back to the airport train station and caught a train into town.

With forewarning we would probably have taken the alternative route offered by cycle.travel from Guspini to Cagliari, which sensibly drops you into Cagliari from the north-east side, which is less infected by autostraditis.