Of course we need to address the high density traffic on our motorways, but different speeds for different lanes sounds both dangerous and impossible to police. (just like mobile phones).Nothing will be of much help to people on the M25 who can't get to 40mph very often, anyway. What is badly needed is educating drivers in the correct way to use the motorways, there are too many drivers who insist on staying in the middle lane doing 70 mph recognised as 'MIDDLE LANE MIMSERS' we also have others who insist on moving from lane to lane in heavy traffic hoping to save a space. And don't forget the drivers who are unable to adjust their speed to maintain proper distances, if they could manage this, it would stop this idiotic panic breaking and maintain steady traffic flow. We should also penalise drivers of lorries who insist on overtaking other lorries going 1mile an hour slower than they are this has the effect of creating a two lane.
I REST MY CASE.
Sylvie - Gloucestershire

Sylvia, Stroud, Gloucestershire

quoting Ruth Kelly "The trial shows there is a real culture change. People are focusing on the way they are driving and there is almost complete compliance with the limit" The reason for compliance is due to the deployment of average speed cameras. What's wrong with variable limits from the normal speed limit during peak hours to 100mph between 12am and 5am. It's quite safe even at over 100mph or even 150mph+ on an empty motorway as demonstrated by the Germans on their autobahns.

Bob, London,

The variable speed zone is reacting to the bunching that is inevitable when human reactions are involved in dense traffic. Its trying to prevent the phantom congestion building by slowing the traffic arriving at the back of it. Problem is you ignore the speed limits and consequently arrive in the queue.

Do as the system asks, stick to the speed limits and you might never see the queue. You'll then complain that the speed limit was spurious but in fact the system will have done its job, your journey will indeed be quicker and also probably safer.

Pete, Edinburgh,

Over half of drivers admit to speeding on the motorway yet they are still the safest place to drive, what does that tell you?

ed, ottawa, Canada

Whenever I use the M25 the only significant parts that I always hit traffic on (not accouting for accidents) is when I enter the variable speed limit zone. This bunches up all the drivers who crawl along at the limit, and as soon as the zone ends all speed up straight away to 70 or more. How does this "reduce average journey times?"

Ian, Kent,

Thank God I have cruise control. I have to admit to selecting the appropriate speed and then letting technology take its course. I must admit to sitting in the left lane (not the middle one) and have a long line of similar people obeying the limits behind me.
I normally select the limit speed plus 1 mph and it works!
I expect that I could go up to 5 mph faster but - why take the risk?
I've used this for the past few years and never had a single speeding ticket yet!

Graham Probert, Camberley, surrey

Speed cameras on motorways? Whatever next?

peter, reading, berks

the M6 on any afternoon and especially Fridays is already so congested that 40mph would be a pipe dream.

what worries me is the thought of people looking at their speedos rather than the road. It gives the govt the fig leaf of action and saves them having to spend the money they get from motoring on roads.

Just wait for the accident statistics to go up.

Trevor, Oxford,

The real issue on motorways is not one of speed or the so-called ripple effect. Rather, it is the lack of maintenance of a 'safe' distance between cars. It the focus was on this particular aspect of driving habits and not on speed there would be a marked improvement in safely and journey times.

Pol, London,

OK fine, so I can see how a lower speed limit would help to stop the dangerous "accelerate-brake-accelerate" ripple effect that you get on crowded motorways. However, I cannot see how the government's enforcement cameras would solve the multitude of of other issues that reduce traffic capacity.

Some behaviours actually require driver education to change, preferably by a full-time, fully trained, police officer with a nice big pad of tickets for those who fail the attitude test.

Examples of what I'm talking about include middle lane hoggers, 56mph-limited lorries overtaking 55mph-limited ones, people who jink from lane to lane in heavy traffic trying to get one car space ahead and people who leave far too little space from the car in front to adjust speed without braking.

Using variable speed limits and revenue cameras to try to address underlying problems like this is the veritable sticky plaster on the bleeding gash that is inconsiderate driver behaviour.

Chris Pickles, Riddlesden, UK

Good idea. Although i would still recommend that the "Sunday drivers" and Middle lane motorway hoggers who tend to populate the motorways at peak times ought to stick to the left hand lane and leave the inside lane to those who have things to do and places to be.

ANDREW EZEA, Hackney, LONDON

Brilliant idea but not going far enough. The new, 40 mph M42 motorway should certainly be re-named B42M.

Mariusz Kuklinski, London,