London is the most congested city in Europe, according to new research.
A study by transport information company Inrix found that the capital's drivers spent 12 working days (96 hours) stuck in traffic last year.
This is 14 hours more than the total for 2013. Researchers attributed the rise in congestion to economic growth and increased urban populations.
The latest figures show that London has overtaken Brussels to become the continent's most congested location, with 74 hours wasted in the Belgian capital in 2014.
The second most congested area in the UK is Greater Manchester with 52 hours lost, while Merseyside, Belfast and Birmingham were third with 37 wasted hours.
The biggest increases in congestion by percentage were seen in North Staffordshire (37%) and the Coventry and Warwickshire area (33%), where drivers sat idle in traffic for 26 and 28 hours respectively.
Bryan Mistele, president of Inrix, said: "For the third year running, traffic in the UK is up.
"The strong growth of the UK economy and rise in urban populations have resulted in an increase in the demand for road travel, significantly driving levels of congestion up across the country."
Transport for London's chief operating officer for surface transport Garrett Emmerson, said: "We are seeing unprecedented increases in population and this, combined with strong economic growth and the consequent increase in building and construction, creates more traffic.
"To tackle this, we need continued, sustained investment to boost capacity and modernise London's road network."