M42 Speed Limits Now
This page lists the speed limits National Highways reports on the M42 — variable limits set on the gantries and limits through roadworks — with the junctions and direction each one covers.
On the M42 right now there are a total of 2 speed restriction signs:
There are 0 stretches of road with a speed limit on the overhead signals
and there are 2 stretches with a roadworks speed limit in force
Checked 03:52 Sat 26 Sept 2026 These are the variable speed limits National Highways set on the overhead signals, usually for queues, incidents or roadworks.
Red ring = mandatory. A speed in a red ring is the legal limit. A number without the ring is an advisory speed. National Highways change these every few minutes, so we show when each was set.
⚠ Our last check of the speed signals was more than an hour ago, so we have hidden the speed limits until we check again.
2 speed limits on this page
Roadworks Speed Limits in Force Now
Temporary limits National Highways have set for roadworks, in force at our last check.
M42 Northbound — 1 stretch roadworks
link road from M6 J4A southbound to M42 J8
10:4723 Sept 2026set 3 days ago⚠ 3 days old✓ Checked by us 03:52
Roadworks Speed Limit
M42 Southbound — 1 stretch roadworks
link road from M6 J4A southbound to M42 J8 southbound
10:4723 Sept 2026set 3 days ago⚠ 3 days old✓ Checked by us 03:52
Roadworks Speed Limit
Source: National Highways’ Speed Managed Areas data, as at 03:52 Sat 26 Sept 2026. Speeds converted from km/h to mph. Powered by National Highways’ Transport Data Feeds.
Where the M42 has variable speed limits
The M42 was the pilot for Active Traffic Management, introduced in 2006 between Junction 3A and Junction 7. The junction list published for the road shows the variable speed limit starting at Junction 3A northbound and ending just after the Junction 9 area, where the signs point to Coleshill and Kingsbury. It was extended there as part of the first phase of the managed motorways roll-out.
A limit shown in a red ring on a gantry is mandatory. When no limit is shown, the national limit applies.
What the pilot changed
Between 2006 and 2007, journey times on the pilot stretch fell by 26% northbound and 9% southbound, and journey time variability fell by 27%. Those figures are why the approach spread to other motorways.
Managed stretches on the neighbouring roads
When the pilot was extended, the same kind of system went onto the M6 as far as its Junction 5 and onto the approach to the M42 at the northern end of the M40. So if you join the M42 from either of those roads near Birmingham, you may already have been driving under variable limits before you reach it.
Roadworks limits count too
A speed limit through roadworks is enforced exactly like a variable limit. Both appear on this page. If you only want one kind, use the filter.
The busiest part of the road
The stretch with variable limits is the busiest part of the M42: the Department for Transport’s 2025 counts put Junction 4 to Junction 5, between Shirley and Solihull, at 136,724 vehicles a day, the highest on the road.
Outside the managed stretch
From the M5 to Junction 3A, and from Junction 9 north to Junction 11, the M42 is a conventional motorway. Limits there are more likely to come from roadworks than from gantries — see M42 roadworks.
For what the gantries are saying in words, see M42 overhead signs. The neighbouring managed stretches on the M40 and the M6 are covered by M40 Traffic and M6 Traffic.
Traffic count figures on this page are from the Department for Transport road traffic statistics, 2025.