M5 slip road closure j16 no advanced warning from M4 Wales 23/6

Hi there On the evening of 23rd June approaching Almondsbury from Wales the M4 onto M5 south slip at the interchange was shut for roadworks however there was absolutely nothing in advance to warn of it, had there been advanced warning drivers could have had time to alter to less lengthy diversions such as the M4 J19 or M49 junction instead of a much longer detour up the M5 to J14 and back. It also resulted in other motorists taking life risking last minute manoeuvres to re-join the M4 across the hatchings risking a crash. (not to say it defends doing that but none the less would reduce the temptation if signs were correctly warning us in the first place) I plead you do a better job at advance warnings of road closures (and that means more than a junction in advance instead of only at the very last minute when it's too late to avoid a longer diversion when there could have been shorter ones. This isn't the first time this has happened recently around this area so please work on this? Thank you