The quality of road markings is in rapid decline, particularly in Scotland.
As many as 40% of markings on Scotland's motorways and dual-carriageway roads need immediate replacement. And 40% of markings on dual carriageways in Wales also need immediate replacement, found a survey by the Road Safety Markings Association.
Looking at more than 4,500 miles of white lines across major routes in Britain, the survey found 38% of English motorways and 36% of Highways Agency-maintained English dual carriageways are in need of immediate or scheduled repairs. In addition, 25% of markings on the agency's single carriageway roads need replacing now, with 19% needing scheduled repairs.
The Highways Agency (HA) is responsible for England's motorways and major A-roads, while the Scottish and Welsh governments look after the rest of Britain's motorways and major roads.
Roads Safety Markings Association national director George Lee said there is "clear evidence of significant decline" in HA markings, while the Scottish and Welsh governments are "as much at fault as the HA".
He continued: "Our report shows that national standards are not being enforced and that the quality of road markings is declining at an alarming rate. We strongly suspect that the layers of bureaucracy built into the system of maintaining HA roads is stifling results. Taxpayers are paying, but the funds are simply not going on the roads."
According to the survey, the poorest stretch of English motorway for road markings is the M6 between Wigan and Standish in north west England, while the best stretch is the M5 between Tiverton and Tewkesbury in south west England.
The survey showed that in Wales the worst stretch of dual carriageway is a section of the A5156 at Wrexham, while the worst motorway in Scotland was a north-bound section of the M90 between Dunfermline and Perth.
A spokesman for the Highways Agency said: "Where markings on sections of road are found to be sub-standard and require urgent improvement, we take prompt action to remedy them... The survey was not comprehensive, and it is not clear how they chose which parts of our network to survey. Furthermore, they misquote the standards for quality of lane markings within their report."
A Scottish Government spokesman said: "An additional £1 million has been identified from road safety budgets this year specifically to address the issue of road markings. In the face of Westminster-imposed cuts to the Scottish budget, increasing traffic levels and the impact of severe weather, all those with responsibilities for maintaining roads face a considerable challenge to retain road standards."