More sickening news; it's actually beginning to make me think twice. Way too common now. I have an old friend from years ago, who is about that age and lives in High Wycombe, and is a cyclist. I'll be watching for updates and hoping it's not him; but whoever the victims are also have friends and family left behind. So sad, and without speculating too much - probably easily avoidable if people would drive as they are supposed to. RIP the 2 cyclists; ride free forever.
"Old Dashwood Hill" https://www.openstreetmap.org/way/100277258 appears to be one of those bits of old A40 which has been bypassed by later "improvements" but not left connected or reconnected to neighbouring quieter roads, so cyclists pretty much have to ride the current NSL A40 to get anywhere east from it, and to use Old Dashwood Hill westwards/uphill (so you've not got motorists up your bum while you climb) means turning right across the A40 twice to get on and off of it. Of course it needs someone to make a big mistake for anyone to die, but that sort of outdated road design seems like inviting it.