When the bridge was built over Loch Creran it took about 7km off the distance of the Twilight 600km perm version of the Daylight.
Riders could either make up the distance by riding onto Oban after the Connel Bridge, or could go round Loch Creran shunning the bridge and use a new info control.
Sadly lacking in info control material, the ingenious Duncan Peet once put "How many windmills can you see?" as the question. Genius. 
Kinbuck just North of Dunblane is the Info Control capital of Scotland. It's been keeping riders off the A9 dual carriageway for decades.
As I remember it, a sign at the head of the loch was used for an info on Port Navigation, the only time I've stopped on a ride for a "fag" break, as the guy I was riding with (who'd never done an Imperial let alone 200 before) decided he wanted a smoke when we got there.
Of course, there was a Right of Way maintained across the old railway bridge...
The current Perm card has Oban as a control
Kinbuck's handy, Braco puts you either over Sheriffmuir if heading south or onto the A9 if heading west, I've accepted the overdistance on DIYs as Braco at least has a shop.
But when heading east/west I've taken to using the Auchinlay road from Cromlix.
The carse of Gowrie's one I've not figured out how to deal with yet, google handily sends you along the little used pavement on the south side of the A90, but anyone with any sense goes up Kinnoul, then along to Errol to which is enough for google to keep you off the A90, but there's nothing up at the Kinnoul car park except for doggers and mountain bikers.
Without info controls we'd be stuffed round here.
