The aim is to spot problem areas that could make customers bad-tempered and more likely to get involved in disorderly incidents.
Constable Tony Marsh, of Cheltenham police's licensing department, sends written reports to licensees advising them how to improve the pub's environment. He said one priority for licensees was to ensure that customers are served in the proper order at busy times. "When you queue in a supermarket you are in competition with everyone else there. You are looking for the shortest queue and making calculations about which one will get through first. People get wound up in these circumstances and their temperature goes up.
"If you transfer that situation to a bar in a pub, you are in a queue which is not easily defined. You know precisely where you are in the order, but the important question is: does the person at the bar know?"
People being served out of order could lead to tension which might boil up to violence and disorder on the streets outside, he warned. Lighting at bars is also important because if it is harsh and bright it makes people's features look harder and that also increases tension.
"We are not telling licensees how to run their pubs. What we do is give them a report on our findings. It is up to them to address anything which we perceive can affect their customers' behaviour. What we are doing is more of a service than an enforcement measure," he said.
The five officers taking part in the survey arrive at pubs at about 8.30pm and keep them under observation until closing time. But not all the town's landlords have welcomed the scheme. Keith Macauley-Fraser, who runs the Hogshead, said supermarket-style queueing systems would never work in the atmosphere of a pub.