GMB says average journey times to work have slowed down over the last five years.
The union’s study is based on the latest official statistics and shows that the average commute from home to work increased from 27 to 29 minutes between 2011 and 2016.
For the UK’s 16 million drivers, this equated to up to 14 extra hours behind the wheel last year, or 230 million hours shared between all drivers.
Rail passengers endured the longest average journeys, with the average passenger facing a gruelling 66 minute commute to work. Bus and motorbike journeys to work suffered some of the biggest increases in commuting times.
Only London Underground and light rail passengers reported faster journeys, following investment in existing and new lines.
The figures suggest that some people in insecure work face much longer journeys, with agency workers reporting that their travel to work lasted a quarter longer than average.
Eight of the areas with the ten longest average commutes were in London, and all were in the South. 
The union said today that worsening congestion, insecure employment, unaffordable housing and the Government’s failure to invest in transport networks were all factors in the slowdown.
Jude Brimble, GMB National Secretary, said, “A couple of minutes on your journey to work might not sound like much to some people, but that works out at 14 hours a year stuck in traffic instead of being at home with loved ones.
“This isn’t just bad for commuters and the economy – it’s a huge strain on the people who build and maintain our transport infrastructure, as well as public transport workers like our members in the bus industry.
“These shocking figures are also yet more proof that so-called ‘flexible working’ is often anything but, with agency and shift workers facing much longer average commutes than people on permanent contracts.
“Longer commutes are a huge detriment to ordinary workers, who are already facing real-terms pay cuts, pension scheme devaluations, extra hours and worsened job security when they do get to work.”