Thursday, 23 August 2007

Exclusive: Blackwall Tunnel Exposé

by Charles Pooter

Update: To Wikipedians and others, I respectfully request that you do not attempt to hotlink straight to the Blackwall Tunnel PDF report referenced in this article. Instead, please respect independent journalism and link to this blog post.

The Blackwall Tunnel in East London is one of the major Thames crossings for motor vehicles. Until recently the tunnel operated a "tidal flow" system. This added an extra Northbound lane in the usually Southbound tunnel in the morning rush hour, easing congestion and allowing a greater number of commuters to use the tunnels to reach their North London jobs from their South London homes.

In April of this year Transport for London ended the tidal flow system. The decision was made suddenly without any warning or consultation. TFL justified the decision thus:

“…an increase in dangerous driving behaviour, including overtaking in the tunnel, has led the Metropolitan Police and Transport for London to bring an end to this system…”
However since the scheme ended, with the resulting congestion South of the river, some are suspicious that TFL had an ulterior motive for ending the scheme:
“If safety is the real issue, why not implement average speed check cameras through the tunnel and a higher police presence. The mayhem that has been left on the south side of the tunnel will undoubtedly result in more accidents there instead.

Is this the Mayor deliberately trying to mess up traffic flow in the area to ease the way for one of his other schemes? All of these seem attractive when faced with the disaster he is causing with this scheme:

- The proposed £3.50 charge for using the tunnel
- Extending Congestion Charging to the Docklands and Greenwich
- Thames Gateway Bridge”
With these questions in mind, a Little Man, What Now? correspondent (who wishes to remain anonymous) filed a Freedom of Information Act request with Transport for London and, after the maximum amount of time allowed by the law, they sent back some interesting results.

According to the documents we have obtained, in 1996 TFL commissioned Mott MacDonald to produce an independent traffic and safety review for the Blackwall Tunnel tidal flow system.

The in-depth report contains a review of accidents within the tunnel, advanced modelling of tidal flow operations and a review of the current arrangements for traffic managements and signing. It then goes on to make recommendations for the future of the scheme. One thing is for certain: the report made it clear that ending the scheme would mean more congestion and that there was plenty of room for improvement to the safety of the scheme without having to end it entirely. TFL sent the document in hard copy, presumably to prevent easy dissemination, but we have scanned it in and converted it to PDF for download:

Some notable quotes from the report:

The net effect of the Tidal Flow operations is to typically increase overall northbound capacity by nearly 20 percent during the morning peak periods typically implemented and removed 3 times between 0615 and 0915 hours on weekday mornings [pg 53]

In terms of overall network statistics, the removal of Tidal flow operations would reduce overall average network speed and increase fuel consumption [pg 53]

It is also noted that in tunnel operations of this type, detailed monitoring and incident management procedures are required, even without tidal flow operations. As such the incremental cost of operating, maintaining and policing this, tidal flow movements is likely to be substantially lower than for a normal road. [pg 53]

The accident risk has shown that the proportion of accidents occurring in and around tidal flow operations is not significantly higher than would normally be expected on this type of road with this volume of traffic, and that the overall wider area effects are small. On the basis of the accident records available it is recommended that accident mitigation should be focused in the first instance on speed management aspects, and specifically on the deficiencies, limitations, and in some cases, inconsistencies in the signing, signalling and road marking regime. [pg 54] [all emphasis ours]”

With an in-depth report like this in their hands, why did TFL end the scheme on the basis of some anecdotal evidence and CCTV footage from the police? We can only assume that they do indeed have an ulterior motive.

Other recent London stories:

A Police Operation at a London Tube Station
Beneath London
Birthplace of Communism Converted to Flats
Sikh Demonstration
The Wilberforce Oak


Chuck Unsworth said...

Good piece. Nicely researched and argued. I wish you well with this, but I suspect that little or no reaction is Red Ken's move on this one.

It needs extended coverage elsewhere - MSM probably.

But no one should harbour any illusions, our political leaders are well capable of engineering such things and frequently do. Didn't Ken get his people to tinker with the traffic control systems before - amongst other wheezes?

gerald hartup said...

Congratulations on digging this out.
I am curious about the use of Freedom of Information. Is the general effect just to slow down the provision of information rather than to extend our right to know?
Why do we need to use freedom of Information to get this infromation?

Charles Pooter said...


I'm not sure I understand your question. There is no rule saying that public bodies have to automatically publich internal reports, but if you suspect that a public body may have documents that are interesting they must have a good reason (within the law) for not supplying them under the FOIA. In this respect the law is very useful for public-spirited trouble-makers (like our anonymous correspondent), which I'm sure is why MPs are now regretting its existence!

Major Gripe said...

Unbelievable - I really hate that mayor. I've linked you in my post about this - interestingly enough, when I called them a few months ago to ask for the CCTV footage of accidents and near misses that they had promised on their website to give anyone who asked, they told me that I couldn't have it.

Well done for getting hold of this. Top rate journalism.

Pritchard Buckminster said...

I hope I am treading on no-one's toes here but have up-loaded this piece's address to the BBC's "suggest a story we cover" site. You never know.....