A217 in Hammersmith and Fulham is UK's most delayed A-road

Drivers on the A217 in Hammersmith and Fulham are experiencing the longest delays of any A-road in Britain. Analysis of traffic data shows drivers on this route lose an average of four minutes and 23 seconds for every mile travelled. This figure is more than six times the median delay of 43 seconds found across 266 roads studied nationally.

London's roads dominate delays

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The study, conducted by Marshall Motor Group using 2025 Department for Transport traffic and congestion data, focused on locally managed A-roads with daily vehicle volumes of at least 25,000. London's high-traffic A-roads experience the highest typical delays of any region in England. Across the 68 London roads included, the median delay was 63 seconds per mile, compared to 52.2 seconds in the East Midlands and 23.9 seconds in the South East.

Other routes in the capital also feature prominently in the list of delayed roads. The A2 in Lewisham recorded an average delay of three minutes and 45 seconds per mile. In Camden, the A41 experiences delays of two minutes and 35 seconds per mile, while the A312 in Ealing sees drivers lose two minutes and 33 seconds per mile.

Fifteen of Britain's 20 worst-performing roads were identified as being in London. Ben Welham, a motoring expert at Marshall Motor Group, commented that factors such as junctions, traffic lights, and merging traffic contribute to congestion on busy A-roads. He noted that even modest delays can accumulate for daily commuters, particularly when roadworks or incidents occur.

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Traffic volume versus delay

The analysis also highlighted that high traffic volume does not always equate to long delays. The A40 in Hillingdon, which carries over 104,000 vehicles daily, recorded the lowest additional delay per mile in London at just 8.2 seconds. In contrast, the A217 in Hammersmith and Fulham, with a daily volume of 36,900 vehicles, experiences significantly longer delays. Mr Welham suggested that road design and traffic flow management play a critical role in mitigating congestion.

Outside of London, the A4150 in Wolverhampton recorded the worst delay at two minutes 12 seconds per mile. Other significantly delayed routes outside the capital include the A5460 in Leicester (two minutes 11 seconds per mile) and the A4161 in Cardiff (just under two minutes per mile).

Drivers experiencing regular delays are advised by Mr Welham to check live traffic updates before setting off and to allow extra time for their journeys. He also suggested that avoiding unnecessary acceleration and braking in slow traffic can help make journeys easier and reduce fuel consumption.