20th April - Audax fail

Central London CTC are running a couple of Audax events in July - 1 is a 200k and the other a 100k. The latter is listed as an ideal first time Audax so I thought I'd give the route a go to see how it would be. The actual event starts at 10am but I didn't get to the start point until 1.40 so I was going to be pushing it a bit to get round, especially as it was on roads I didn't know and therefore I'd be making regular stops to navigate. Also the traffic on the early section was likely to be heavier than on a weekend.
The route is here http://www.gmap-pedometer.com/?r=2727276 and it's not until after Barnet that it starts being a bit nicer for cycling. Anyway, I made the halfway point in 2.5 hours which wasn't too bad (it seemed reasonably hilly) as on the actual run you need to take between 1hr48 and 4hrs. I turned straight round and started heading back. All went well until about mile 45 where I missed a turn and ended up going all the way to Hertford. Realising my mistake, I tried to head along the B1000 to rejoin the route but again I missed the turning and continued to Welwyn GC. I thought about taking the B195 and trying again to rejoin the route but by now the traffic had built up, the daylight and heat of the day was fading and I decided to call it a day, catching the train back to Finsbury Park. I still managed to clock up 66 miles for the day but this route is definitely classed as unfinished business.