We have stayed here previously, and so we were prepared for the road traffic noise. This is still a problem, because the site is alongside a busy road. However,behind the site, there is a sewerage plant,and the noise from generators/compressors/machinery runs all night. The road traffic hides the sound of the sewerage works during the day,but you can hear it all night long.  Spoiled our holiday, to the extent that we explored a commercial site, Swiss Farm, about 400 yards away. This site is much further back from the road, and is very large, and would be very busy during school holidays, but was quiet at this time of the year, and we will be using this as an alternative, next time we visit the Chilterns.