M25 still crucial for South East van fleets as Geotab flags western congestion hotspots

New Geotab research marks 40 years since the M25 opened in full and finds the motorway remains essential for South East England van operators, even as delays and unreliable journey times frustrate drivers. The data shows most of the ring road moves relatively well, but the worst congestion is concentrated around the M3, M4 and M40 interchanges in the west.

Why it matters: - The M25 remains a core business route for South East England van fleets. - Delays on the motorway can drive customer complaints, higher fuel costs and missed jobs. - Geotab’s analysis suggests the main issue is not constant gridlock, but unreliable journey times in specific locations and peak periods.

What happened: - Geotab released research to mark 40 years since the M25 opened in full. - Opinion Matters surveyed 1,000 van drivers in South East England who regularly use the motorway between 15 and 23 September 2026. - Geotab also analysed connected vehicle data from 12 sample weeks between September 2025 and August 2026 across 58 directional junction-to-junction sections of the M25. - The dataset is a sample rather than a census of all M25 traffic and is weighted toward commercial fleets.

The details: - 97% of surveyed van drivers said the M25 is important to the daily operation of their business, and 62% said it is very important. - 84% said their business could not operate as effectively without the M25. - 84% said the motorway allows them to serve a wider geographical area. - 82% described the M25 as indispensable to their business. - 80% said the alternatives to using the motorway are worse. - 81% said the M25 causes delays. - 79% described it as frustrating. - 80% said it is less reliable than five years ago. - 30% said customer complaints are a common consequence of M25 delays. - 29% reported additional fuel costs. - 28% cited late deliveries or collections. - 25% said they have had to decline jobs because the journey can be too unpredictable. - Geotab found that 46 of the M25’s 58 directional sections operate at 80% or more of their posted speed limit on average. - The eight most congested sections are all between Junctions 10 and 20 in the west, around the M3, M4 and M40 interchanges. - The worst pinch point is Junction 12 to Junction 11 anticlockwise, from Thorpe towards Chertsey, where traffic averages 68% of the speed limit. - The Heathrow corridor is also a pressure point. - Junction 15 to Junction 16 clockwise runs at 70% of the speed limit on average, while the reverse direction runs at 72%. - Junction 14 to Junction 15 clockwise is the slowest section on the ring, averaging 44.6 mph. - Journey times can swing sharply by time of day. - On the clockwise stretch between Junctions 14 and 15, a trip that takes 9.2 minutes at 4pm drops to three minutes at 7pm. - On Junction 17 to Junction 16 anticlockwise, a trip that takes 15.6 minutes at 7am takes 6.6 minutes at 7pm. - On Junction 20 to Junction 19 and Junction 13 to Junction 12 anticlockwise, journey times during the worst 5% of working-day hours are twice as long as normal. - On Junction 13 to Junction 12, almost a third of working hours are at least 30% slower than normal. - The survey found drivers do not agree with the data on which sections are the biggest problem areas. - Clockwise, respondents most often named Junction 3 to Junction 4, Junction 2 to Junction 3 and Junction 4 to Junction 5. - Anticlockwise, respondents most often named Junction 28 to Junction 27, Junction 29 to Junction 28 and Junction 27 to Junction 26. - Geotab’s data shows none of those six sections ranks among the motorway’s worst overall performers. - All six of those sections have their slowest working-day journey at 7am. - On Junction 29 to Junction 28 anticlockwise, journey time rises by 57%, from 3.1 minutes in the fastest working-day hour to 4.8 minutes at 7am. - Among Geotab-connected vehicles, 6am is the busiest hour of the day, not the conventional 8am commuter rush. - Traffic at 6am still moves at an average of 57.7 mph. - Speeds dip at 7am, recover through the middle of the day and reach their lowest average levels between 4pm and 5pm. - Across the 12 weeks sampled, Geotab identified 659 periods when a section’s speed fell to 70% or less of its normal level. - The analysis also found 236 disruptions lasting two hours or longer. - Monday and Friday recorded the most disruptions. - The eight most congested sections are all between Junctions 10 and 20, and six of the eight least reliable sections are on the same western stretch.

Between the lines: - The data suggests drivers are reacting to delay variability and peak-time frustration, not just average road speed. - The west side of the M25 stands out as the main operational risk area for fleets. - Aaron Jarvis, vice president EMEA at Geotab, said there is no practical alternative for many operators and that the data can help fleets adjust departure times and plan around weekday peaks. - Jarvis also said faster incident detection and clearance could make a real difference. - The survey’s top requested improvements were faster incident detection and clearance at 11.7%, a consistent 50 mph peak-time speed limit at 11.4%, better coordination of roadworks at 11.3% and better live traffic and routing information at 10.9%. - Other responses favored additional lanes on the worst-delayed sections at 10.2%, junction upgrades at 9.8%, a consistent 60 mph peak-time limit at 9.2%, improved service areas at 9.1%, more reliable journey-time forecasts at 8.4% and improved charging infrastructure at 7.9%.

What's next: - Geotab says the findings point to targeted interventions rather than a single fix. - The priorities include quicker responses to incidents, better driver information, improved roadworks coordination and closer attention to the western M25. - The broader challenge for the next decade is improving reliability on the sections that have the biggest impact on business operations.

The bottom line: - The M25 is still indispensable to van fleets, but the biggest gains now appear likely to come from better management of the motorway’s worst bottlenecks, not from trying to eliminate congestion everywhere.