Why lots of drivers are being caught by M4 speed cameras
Many drivers using the M4 around Swindon and Wiltshire are being caught speeding despite travelling below the national 70mph limit. The main reason is the increasing use of temporary and variable speed limits, which are enforced automatically by speed cameras. On busy stretches of the M4 -- particularly between junctions 19 and 20 -- speed limits often drop to 50mph or 60mph because of congestion, roadworks or safety concerns.
Cameras enforce the limit shown on overhead gantries at that exact moment, not the national speed limit. Several motorists have been taken to court after being recorded at speeds such as 67mph or 72mph, which many drivers still assume is acceptable on a motorway. In law, even a few miles per hour over a temporary limit can result in fines and penalty points.
On April 25, the Adver reported[1] that a man was fined after being caught by an automated speed camera driving at 68mph on the M4. Omar Ali, 58, of Goodhind Street, Bristol, was travelling behind the wheel of a Lexus on March 23, 2025. Variable speed restrictions were in place at the time and the temporary speed limit was 50mph on the busy motorway.
He was fined and handed four penalty points. Joseph Amenebede, 38, of Dydale Road, Taw Hill, was also fined and given three penalty points after driving 67mph at a spot on the M4 where a 50mph restriction had been enforced. He was travelling eastbound near Junction 19 in September 2025.
Confusion has been made worse by concerns over faulty speed camera systems. In early 2026, it emerged that some National Highways cameras on the M4 may have been enforcing limits before signs had fully updated, leading to thousands of potentially incorrect fines dating back several years. The Department for Transport ordered an independent review, with some drivers now in line for refunds or points being removed.
There has also been wider public debate about whether drivers spot the signage clearly enough -- especially at night or in heavy traffic -- and whether enforcement feels disproportionate when motorists are travelling close to motorway speeds rather than racing.
Authorities maintain that variable speed cameras are essential for traffic flow and safety, but the volume of prosecutions suggests many drivers still underestimate how closely these limits are monitored.