M4 Motorway Closure
Please be advised that the M4 between junctions 18 and 19 will be closed in both directions from 19:00 on 21st March, affecting road freight.
www.agi.globalHere are the latest publicly reported updates on M4 closures I can share right now:
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There have been ongoing and planned closures on the M4 in various segments, often tied to bridge works and resurfacing. For example, overnight eastbound closures between junctions 16 and 15 were scheduled for several weeks in late 2025, forming part of a larger resurfacing program. These closures typically occur during off-peak hours and include detours.[1]
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Weekend closures between junctions 18 and 19 have been used to facilitate demolition or construction work on the adjacent Badminton Road bridge, with expected significant travel impacts and advisories to avoid the area if possible.[9][1]
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There have been reports of emergency or exceptional closures in response to specific incidents or infrastructure needs, such as power-line or bridge-related works, which can lead to full motorway closures and long delays in the affected sections.[3][5]
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Travel services and updates from transport and news outlets typically offer live delay information, alternative routings, and recommended planning ahead when a closure is in place.[3][9]
If you’d like, I can narrow this down to a specific segment (e.g., J10–J11 near Reading, or J18–J19 near Bath/Bristol), or pull the very latest advisory from National Highways for your exact date and location. I can also provide a brief options guide for planning around closures (detour routes, travel time estimates, and alternatives).