Did this as part of Brighton training. 

The car park was at a school away from the centre of town, a bit of a walk but no traffic problems and plenty of parking.  There were plenty of places for coffee and food in the town centre  open before the race.

I arrived at the start quite late, so don't know if I missed a briefing.  Getting to my normal spot nearer the back wasn't too difficult.  As well as the normal single loos, there was a urinal area for men which helped with queues, though certain spots weren't that private.

The race initially started through the centre of town, then left on one of the main roads out.  This wasn't closed, so there was some traffic passing the runners, and pavements only at certain spots. 

After a mile or two we turned onto back roads up in the hills towards Ashridge.  There wasn't much in the way of traffic on the roads, and plenty of marshalls around, and sufficient water stations.

The hills aren't too bad, long steady ones rather than anything too steep, and the final mile or so is a long downhill (which hurt my foot slightly), so a quick finish is possible.

Didn't use the baggage drop, so got away quickly into town.  Berko has a lot of places to eat, and is easy to get to by train (the station is close to the start).  It was quite a long uphill to the school car park though.

Well worth doing if you don't mind a few hills with nice Chiltern scenery.