The report compares congestion levels in 2012 versus 2011 in 161 cities and across five continents and based on real travel time data captured by vehicles driving the entire road network, using over six trillion data measurements.

The top ten most congested cities in the UK, ranked by overall Congestion Level, in 2012 are:

1. Belfast 32.1%
2. Bristol 31%
3. London 27.5%
4. Leeds-Bradford 26.2%
5. Nottingham 24.4%
6. Manchester 24.2%
7. Sheffield 23%
8. Birmingham 21.6%
9. Liverpool 21.4%
10. Newcastle 20.9%
11. Glasgow 18.3% 

‘TomTom’s Annual Congestion Index provides accurate insight into the world’s most congested cities,’ said Ralf-Peter Schäfer, head of traffic at TomTom.

‘This detailed knowledge of the entire road network helps businesses and governments to make more informed decisions about how best to tackle, and avoid congestion.

‘TomTom’s world-class traffic information also helps drivers get to their destinations faster. Significantly, when used on a large scale, TomTom HD Traffic has the potential to ease congestion in cities and urban areas by routing drivers away from congested areas.’

TomTom’s full Congestion Index, including individual continent and city reports, can be found at www.tomtom.com/congestionindex