The decision to close a motorway is an operational matter for the police. In reaching such a decision they are fully aware of the disruption and inconvenience such a closure might cause. They must however give due priority to ensuring the safety of individuals involved in an incident, of the public at large, of emergency service workers attending an incident and of all other road users.
I understand that on this occasion the road was closed while police officers talked to a vulnerable person on the bridge, who subsequently fell and was killed. Apart from the risk to his own well-being and that of those attempting to help him, his behaviour was distracting motorists from paying due attention to driving safely. I understand that Avon and Somerset Constabulary have informed their Professional Standards Department and the incident has been referred to the Independent Police Complaints Commission.