Which is the busiest or biggest service area?
Inside Cobham, Britain's biggest.
The biggest motorway service area in the UK (and bigger than anything in Ireland) is Cobham on the M25. It stretches across two floors and opened in 2012, filling a large gap on a very busy section of motorway. Its 36-pump petrol station is one of the biggest in Britain. It's difficult to compare like-for-like, but Cobham would be a good candidate for the busiest official service area open to all vehicles in Europe.
As motorway service areas are private businesses, they do not publicise how busy they are. A rudimentary analysis of social media suggests Cobham gets talked about the most by customers. This would tally with our own website analytics, which show that Cobham is searched for the most. We already know it's the biggest, so it's a logical that it would be the busiest as well.
In fact as part of their justification for building Colne Valley services, in June 2021 Welcome Break (who provide some facilities at Cobham) stated unequivocally that Cobham is the UK's busiest service area.
Watford Gap, one of the first service areas to open in the UK, was thought to be the busiest for a long while. A media report in 1988 claimed that Hilton Park was actually the busiest, a claim that was made repeatedly during the 1990s (although the Daily Telegraph did report in 1994 that Membury was the busiest, but this was most likely old data).
Hilton Park's importance would have declined slightly as more service areas opened nearby, including Norton Canes in 2003. It's likely that another site claimed the top spot, with Strensham, Fleet, South Mimms and Toddington being other likely candidates, before Cobham conclusively claimed the title after 2012.
In addition to the biggest and the busiest service area, you could also ask about the busiest single day.
Unsurprisingly there is no official record or way to compare different operators. However, a reasonable guess for the UK would be 31 August 2021.
The summer is always the busiest season for leisure traffic, and the August Bank Holiday is usually where that peaks. August 2021 was especially busy because the recent relaxing of COVID-19 restrictions meant there were many people who would normally go abroad in August, or who would normally go on holiday earlier in the year, but decided to take a holiday in Britain over that weekend instead.
Roadchef said that this August Bank Holiday was "without question, one of the busiest weekends in our trading history". They said the trade at Killington Lake and Taunton Deane was "record breaking", and named Strensham as their busiest single site. Other service areas on the M5 are likely to have a similar story. Across 30 sites and three days Roadchef reported selling 200,000 burgers and 230,000 hot drinks.
The exact results will vary depending on whether you are looking at footfall, profit, turnover or traffic levels; whether you're analysing a whole day or a specific hour; and whether you're looking at one site or the whole country. As a general rule, you're unlikely to see a combination of factors leading to a weekend as busy as that Bank Holiday for a long time.