Travellers heading to Heathrow airport by road this Sunday, 14th August, should be prepared for their journey to be “severely affected” by an Olympics cycle test event.

The 140km London-Surrey Cycle Classic road race does on a loop from central London to Surrey and back, taking in locations including Richmond Park, Hampton Court and Box Hill. Many roads in the area will be “closed, restricted or heavily congested”, including stretches of the M25 approaching Heathrow airport.

Transport for London advises that affected roads will be closed “for the majority of the day”, and says that travel to both Heathrow and Gatwick may also be disrupted.