Speed limits in roadworks

[DuncanL]

Would anyone care to shed some light on the criteria used for setting the temporary speed limit in roadworks? On the M1 at Leceister we have a 40MPH limit enforced by SPECS, on the M25 we have a 40MPH limit and sometimes a 50MPH limit enforced by GATSO, on the M3 we have a 50MPH limit with no enforcement (currently), and the M1 at Sheffield a 50MPH limit - no enforcement.

All of these are for roadworks, I cannot see the M1 Leceister roadworks as being much different from the others (apart from SPECS).

What is the criteria used for the temporary limits?

[rewc]

The lowest posssible, 24/7 even when no workforce to be 'protected', enforced to catch the largest number of motorists.

[BliarOut]

Leicester obviuosly haven't raked in enough cash this year. Interesting that deaths go up when they put Gatso's in roadworks

[madbadger]

Not surpised.

I went through bends in the M1 roadworks with three car abrest, all a foot or so apart in narrow lanes, all travelling at exactly the same speed.

Would have been far safer to have increased the speed to, say, 42 for a bit, but not with SPECS watching.

[Dwight VanDriver]

Understand that general advice of DoT is that that temporary speed limit for roadworks is 20 mph below actual normal limit.

So on a MW/DC you have 50, on single 40. But if other hazard conditions apparent then can be lower.

dvd

[Don]

My approach on these limits is to move over to the left hand lane from wherever I have been, err, making good progress and then to drive 1-2mph below the speed limit right the way through.

By doing this I get myself as our of the way as possible for those who want to go faster.

I also get to watch the pretty bright light as it strobes over those aren't predicting the presence of cameras despite the vast amount of signage...

I am convinced these things do little or no good in terms of safety. But I am constantly astonished at how many seem to utterly ignore the extreme liklihood of copping a fine...

[smeggy]

DuncanL said:

....... on the M3 we have a 50MPH limit with no enforcement (currently).....

It's now enforced.
Two GATSOs went up on the northbound carriageway after J4. A friend reckons he saw one flash

[echo]

Dwight VanDriver said:

Understand that general advice of DoT is that that temporary speed limit for roadworks is 20 mph below actual normal limit. So on a MW/DC you have 50, on single 40. But if other hazard conditions apparent then can be lower. dvd

There is no 'general advice' as far as I'm aware -it's all regulated and mostly down to lane widths, signage sizes and safety zones.
The general rule is that the narrower the running lane(s) and the less space there is for a safety zone - the lower the speed limit needs to be. It's all regulated in 'Chapter 8'.
(safety zone is the 'no-mans-land' between the work area and the live traffic lane(s))

[7db]

to Don. Exactly what I do, and I watch in wonder as the flashes go off...

[Dwight VanDriver]

Echo

Understood this advice was circulated to LA bt DoT in a Circular Roads Memo?

dvd

[esselte]

Don said:

My approach on these limits is to move over to the left hand lane from wherever I have been, err, making good progress and then to drive 1-2mph below the speed limit right the way through. ...

I did this on the M1 in Leicester a few weeks ago and was followed at a distance of 5 microns by a braindead artic driver who,instead of going past me thought he'd have more of a chance if he flashed his headlights in my rear view mirror.Wr

[DuncanL]

echo said:

There is no 'general advice' as far as I'm aware -it's all regulated and mostly down to lane widths, signage sizes and safety zones. The general rule is that the narrower the running lane(s) and the less space there is for a safety zone - the lower the speed limit needs to be. It's all regulated in 'Chapter 8'. (safety zone is the 'no-mans-land' between the work area and the live traffic lane(s))

Hmm .. This still doesn't fully explain everything -
M3 has reduced lane width and 50MPH + GATSO
M1 Leicester has reduced lane width and 40MPH + SPECS

This all does not help my cynicism, maybe Leicester got the lower limit because of the SPECS (what a shocking thought)

I will have a good look at both sites on the way home tonight