A traffic jam is seen as cars head towards the approach tunnel of Heathrow Airport, west London
A traffic jam is seen as cars head towards the approach tunnel of Heathrow Airport, west London, Britain November 26, 2015. Activists opposed to the expansion of London's Heathrow Airport blocked an approach tunnel on Thursday by chaining themselves to a parked vehicle, sowing traffic chaos around Europe's busiest airport. REUTERS/Peter Nicholls