Posts Tagged ‘m42’

Active Traffic Management

October 18th, 2011

As many motorists in the UK will be aware, over the last few years there has been a massive increase in ‘Active Traffic Management,’ which came from a decision to prevent the ‘environmental impact’/cost of widening the M42 motorway south of Bimingham.  Well, as one of the lucky people that call the ‘South of Birmingham’ my home – I’ve benefitted from this new system, and also seen it extended up and down the M6 past Birmingham, just about covering my entire commute to work.

Ok, I’ve only been commuting this route for the past three months, though I have noticed a few key problems with the ‘Active Traffic Management’ system that probably require a more sophisticated form of complaint than a ‘blog rant’ – but who knows, it was worth trying it here first.

For those of you unaware of ‘Active Traffic Management,’ it consists of overhead gantries every x metres along the motorway, with a nice LED sign above each lane showing either the speed limit, a big red ‘X’ for Lane Closed, or an arrow, pointing either to the bottom left, or right, advising the motorist of which lane they should filter into.  There are also big information display board at special intervals (and before junctions) that advise motorists of issues ahead on the motorway network, and provide nice little diagrams for how to get off at any particular junction (as the junction dynamics change depending on the lane closure).  There are also average speed checks along the entire route, as well as nifty ‘traditional’ speed cameras every so often, to catch out the unsuspecting driver who strays above the limit imposed on the overhead sign.

Having my leg broken by a car, you think I’d have a bias towards slowing them down, but surprisingly, I don’t.

The problem for me lies in that there doesn’t appear to be a ‘level of assurance’ in the quality of the overhead sign.  A few months ago I was driving home at 2300 hours from Manchester, and pulled onto the M42.  The traffic was slowed to 50mph by the overhead signs (without a decrement from 70 to 60 to 50), and it was shown that lane closures would be ahead.  The traffic cones soon came into view, and I was shuffled down to the slow lane, with 50mph passing over my head every few metres.  Not long after I’d been driving, the speed limit reduced to 40, and I noticed a car come up behind me, clearly doing more than the 50 they should have been – and not looking like they’d be slowing to the 40 I was adhering to.  I then looked up, and the next sign was showing 20mph.  20MPH!!  I had to either slow down to this new sign, or face the fact the guy behind me was either going to career into me, or into the unsuspecting workmen that this very system was designed to protect.

Luckily for me, and them, they were able to slow down – but not without them rudely beeping their horn (which I know to be illegal past 2300 hours on a weekday).  The speed limit then increased back to 40mph, so I felt a little less bad – but then back down to 30mph.  They must have thought I was teasing them.  When I finally got to the end of the roadworks, I sped up to 70mph as fast as possible, and they joined me – pulling funny faces and signs out of their window, then speeding off at a speed considerably faster than me.

The problem I have here, is that there should be some legislation (or programming control) preventing the signs decrementing by more than 10mph between two signs.  I understand that in certain emergencies it is necessary to put the signs up immediately – but to have planned works without considering the effect of lowering the speed limit on the motorway to 20mph.. well it just seems ridiculous.

The second problem I had with them (that caused me to write this post in the first place), was on my way home the other night after work.  The motorway was then again brought down to one lane, using the aforementioned arrow system.  It correctly put us down to one lane, then as soon as the cones were signally us all to move over, the signs above changed to show all three lanes open and running at 50mph, despite us being limited to three lanes.  When the cones stopped, there was no difference between what had been shown on the gantries with the lanes closed.  It really annoys me that millions has been spent on this system, yet it is being used incorrectly through laziness.  This is not a technical issue – it is simply a lack of pride in doing a job well.  When thousands of hours of time must have been spent on the technical proposal and the theories into fluid dynamics and traffic movement – the implementers have appeared to ignore any use of controls to keep from adversely affecting traffic flow rather than increasing it.  I’d also love to see a few days a week with the ‘Active Traffic Management’ turned off completely, to confirm whether or not having it on has made a positive different or not.

So when David Cameron and the other ConDems are reading over their legislation on increasing the speed limit to 80mph, please can they spare a couple of hours to look over the crippling ‘Active Traffic Management’ that may – or may not – be improving Britain’s motorways.