Live M3 Traffic Flow Map Now
How fast is the M3 moving right now? This live traffic flow map shows the speed on every stretch of the M3 from Junction 1 at Sunbury to Junction 14 at the M27 outside Southampton, in both directions. Green is moving freely, amber is slow and red is very slow or stopped.
The map is a summary. For the full picture before you set off, see all the latest M3 traffic news, the overhead message signs showing on the M3 right now, and the speed limits on the overhead signs.
Untick all three to see just the speeds. We show the important overhead signs and the mandatory speed limits (red ring); see every overhead sign.
NOTE: The speed flow, overhead sign messages or other information shown on our live traffic speed flow map is updated every few minutes. We cross check the data and aim to provide warnings if there could be a delay or an inaccurate speed reading. There can be occasions, beyond our control, and despite our best efforts where the speed flow could be inaccurate. We cannot therefore guarantee the speed you can expect on any stretch of the motorway is always accurately shown. However we hope you will find our live traffic speed flow map a useful tool in trying to plan your journey. Safe driving.
How to read the M3 speed flow map
London is at the top of the map and Southampton at the bottom. The left-hand line is the eastbound carriageway, towards London, and the right-hand line is westbound, towards Southampton. On the M3, eastbound is the direction many drivers call northbound, and westbound is southbound. Junctions are spaced by the real distance between them, and the miles between each pair are shown on the left. Tap or click any stretch to see its speed and how recently it was measured.
The M3 is just under 60 miles long, so use Show junctions to see only the part you are about to drive, and Colour the road by to switch between plain speed in miles per hour and speed compared with what is normal for that stretch at this time of day.
Services and connecting motorways
A red end on a junction sign with a knife, fork and fuel pump marks services. Connecting motorways, such as the M25 at Junction 2 and the M27 at Junction 14, are shown in blue. Where we run a site for that motorway, a pointing hand shows the way you turn off; tap it to see that motorway’s site.
For every junction with the roads and places it serves, see the map of the M3 junctions.
Where the speeds come from
The speeds come from National Highways’ traffic data, which combines road sensors with vehicle data, and the map is refreshed every five minutes. Where no recent measurement is available for a stretch, the map shows the speed that is normal there at this time of day and says so when you tap it. Road closures reported by National Highways are shown in red with white crosses. Always follow the signs and signals you can see on the road.