After the Sunderland game I spoke with one of the stewards 'organising' the traffic and he said they'd trialled this new system during the summer at the concerts and it worked well.
The problem is the pedestrians just completely ignored all of the signs that were put up directing them along a specific route for their own safety.
Instead they parted the barriers and just pleased themselves, once one does it all the rest follow.
The 'I'm alright Jack and fuck the rest of you' attitude is massively contributing to the delays, it's needs a rethink now as clearly they hadn't factored in selfish twats!