The "fragile nature" of Birmingham's traffic system was exposed again yesterday as thousands of rush hour motorists endured misery when a tunnel was closed following a minor accident.

That is the view of the city's Chamber of Commerce which heavily criticised the traffic network after the accident brought the northern approach to Birmingham to a standstill.

Tailbacks went back from St Chad's Queensway between 9-10.30am after the tunnel was sealed by police.

* What do you think? We want know - get in touch by email, messageboard or feedback form *

Traffic was stationary from the the busy traffic island all the way past Lancaster Circus and up the Aston Expressway to the M6 following the accident, which occurred just after 9am.

A spokesman from the chamber said minor accidents which cause traffic chaos can be "massively costly" to the local business community.

He added: "This just demonstrates the fragile nature of Birmingham's traffic problems. We only need two cars to crash or someone's bumper to fall off. The whole thing is on a knife edge.

"A minor incident will bring the whole city centre to a halt. This is what is wrong with Birmingham's traffic system.

"And if we want to be able to cater for volume transportation, there needs to be an integrated public transport system."

A spokesman from Trafficlink information service said: "Our cameras showed that the M6 was still quite busy because of the accident at about 10am.

" There were certainly queues northbound and a build up of traffic southbound."