Commuters in Brighton and Hove lose 68-hours a year in evening rush hour traffic, according to TomTom.
The city is the fifth worst congested in the country according to a report by the sat nav company – behind only Belfast, London, Edinburgh and Manchester.
Peak-time journeys in Brighton and Hove take 59% longer than they would in free flowing traffic.
On average all journeys nationwide took 29% longer than they should and in Brighton and Hove they take 34% longer.
Congestion levels in the city have also got worse since TomTom carried out the same survey last year.
The percentage figures are calculated using an estimated journey time of 30 minutes.
Worldwide, the worst city was Istanbul, with average journeys taking 58% longer than in free-flowing conditions, rising to as high as 109% in the evening peak.
Mexico City was the second-worst city worldwide, followed by Rio de Janeiro.
Ralf-Peter Schaefer, TomTom Traffic vice-president, said: “Road authorities and local governments can use traffic data to better manage traffic flow and businesses can plan smarter working hours, so their employees avoid travelling during the rush-hour.”
Brighton and Hove City Council work on the £4 million Lewes Road improvement scheme has earned the authority the most improved journey to work accolade at the Smarter Travel Awards on Thursday 5th February.
The council was also shortlisted for the best smarter travel app category in recognition of the relaunched JourneyOn travel planning website which gives residents up to the minute travel options as well information on calories burnt and CO2 produced by different journey choices.
The council impressed judges with the increase in cyclists and bus passengers achieved by the conversion of the 4.5km dual carriageway between the Vogue Gyratory and Falmer into a single carriageway with bus lane with widened cycle lane.
Initial findings from the monitoring of the scheme showed a 7% increase in the number of bus passengers, daily cyclist numbers along the route rose by 14% from 2,085 to 2,383 while general traffic reduced by 13%.
The award is the latest in a number of transport prizes the council has received including the Civitas European City of the Year by for clean transport.
Councillor Ian Davey, lead member for transport at Brighton and Hove City Council, said the council was “delighted” to win the national award.
He said: “One of the main aims of the Lewes Road scheme is to make sustainable forms of transport more attractive, where it is a practical option for those concerned.
“Although the scheme has only been in place for a short period, the initial monitoring is very positive.”
The Vogue Gyratory in Lewes Road, Brighton, will be shut to southbound traffic between Monday December 2 and Friday December 5, from 8 pm until 6 am.
It is one of the final steps in works since July to redesign the junction, which have caused heavy delays. Southbound traffic heading for the city centre will be diverted up Coldean Lane and down Ditchling Road. There will be access-only arrangements as far south as Coombe Road.
There will be no access in or out of Hollingdean Road, Bear Road or Upper Lewes Road. For the first three nights, there will no vehicle access in or out of the Sainsbury’s car park after 8pm. The store will be open as usual until 10pm.
There will be no changes to northbound traffic. New traffic lights are due to be installed the week after the resurfacing, the final stage in the improvements to the scheme.
A spokesman for Brighton and Hove City Council said the resurfacing would have been needed regardless of the changes to the gyratory.
The authority has written to 1,000 local addresses about the plans and has also been talking with local businesses, a spokesman said.
Lead councillor for transport Ian Davey apologised for the disruption but said once finished the junction would be “safer” and “more pleasant.”