Hopes for a safer and improved junction on a busy road known as a motoring blackspot in St Albans are fading after yet another delay.

St Albans district councillors for Colney Heath Jamie Day and Chris Brazier have long campaigned for alterations to the Colney Heath longabout on the A414 after continued accidents, including several fatalities.

They had applauded a promise made last year by Herts county council to spend £60,000 on a new design and installation of traffic lights.

The first phase of the project was supposed to start last November, with the second phase scheduled for 2014/15.

But those plans appear to be in danger of reaching a dead end.

Cllr Day said Herts Police had objected to the proposals and the improvements were cancelled as a result.

Cllr Brazier added: “We have kept campaigning for the work that was agreed and we have been told that a trial will start in September this year.

“The police are still sceptical and unless the trial proves successful, changes to the longabout will be stopped.

“They feel the flow of traffic from the Hatfield roundabout to the London Colney roundabout on the A414 should be left to flow freely.”

Cllr Day added: “They are concerned that more accidents will happen due to the interruption of this flow and people jumping the new traffic lights.”

But the councillors insist the longabout needs to be made safer and more accessible for motorists leaving Colney Heath High Street, Station Road and Colney Heath Lane.

Cllr Brazier said: “Some local residents have to wait for up to 40 minutes in long traffic jams to exit the village and get onto the A414; this is not acceptable.”

A council spokesman said: “There is a fine balance between safety and providing an efficient network for the travelling public. Even minor alterations to a complex junction, such as the longabout, can have a significant impact elsewhere on the highway network.”

The spokesman said that proposals for the junction are “continuing, with a view to carrying out a trial of temporary measures later this year. This will help us to understand the possible impact any permanent alterations may have.”

A spokeswoman for Herts Police said the improvements were a “council decision” and that the police would not comment further until after the trial has been held.