First of all, a definition and a little British history. A trunk road - like a trunk line in railway parlance - is the main route between
destinations and one element of a network. This country's trunk roads network was formally established in 1936 with the passing of the Trunk Roads Act.
This identified roads of national strategic importance and transferred responsibility for them from local authorities to the then Ministry of Transport.
So trunk roads are distinctly government roads in terms of policy, finance, planning and operation. These days the category includes motorways as well as single and dual carriageway all-purpose trunk roads.
Together they represent a small minority of the highways in England - at their most, just 10,500km in total length as opposed to the 250,000km of non-trunk roads which are in the care of local government.
An indication of their importance is that they carry 30% of the total traffic flowing through the country every day, and 50% of the heavy goods vehicles.
The trunk roads network has fluctuated through the years as new roads have been built and old ones - perhaps diminished in importance by being bypassed - have been detrunked. The process involved a change in 'ownership' from central to local government.
'In recent times, local authorities have called for more radical detrunking, claiming there were many trunk roads which displayed important local rather than national characteristics, and whose planning and management should logically be conducted on a local basis,' says the Local Government Association's transport policy officer Vince Christie.
The calls seemed to fall on deaf ears. Then, out of the blue, came government proposals to detrunk 40% of the non-motorway network.
These proposals were contained in New deal for trunk roads in England, an accompanying document to the Integrated Transport White Paper published in July 1998.
The Government's declared intention was to improve the use and maintenance of trunk roads, and it had analysed what constituted England's definitive core network of nationally important routes.
This was substantially smaller than the old trunk roads network. The Government said that it would enter negotiations to transfer responsibility for roads that were now deemed non-core.
'If a road which is now a trunk road does not have significance outside a local highway authority's area, decisions about improvements to that road ought to be taken by the local highway authority,' the document said.
'Local authorities were caught on the hop and their immediate response was a cautious one,' Christie says. On the one hand, what seemed to be on offer was all that they could have hoped for in terms of increased influence and responsibility, while the proposal also represented an ostensibly sound move in planning terms.
When preparing their Local Transport Plans (LTPs) local authorities are required by the Government to emphasise integrated transport. In many cases, authorities likely to gain detrunked routes could contemplate more logical overall plans as key local highways came under their jurisdiction.
On the other hand, trunk roads could well bring with them wide carriageways and big structures which are expensive to maintain. Local authorities wondered if the Government would recognise the true cost of keeping detrunked roads in good order and pass on sufficient funds. If it did initially, would those funds be secure in the long term?
These worries have been voiced loudly, as have others about the impact of the proposals on newly commissioned multi-modal transport studies and the methodology of transfer - bearing in mind that some roads to be detrunked are maintained within Super Agency agreements, while others are up for improvement.
A year of consultation followed publication of A new deal for trunk roads, with the Department of the Environment, Transport and the Regions and its Highways Agency talking to and listening to the likes of the Local Government Association and the CSS (formerly the County Surveyors Society).
One development has been reduction of the original 40% figure for roads to be detrunked to 30%. Those roads to be transferred are to be subjected to conventional detrunking orders under the 1980 Highways Act - the Highways Agency has been at pains to emphasise that acceptance by local authorities of detrunked roads is voluntary.
No roads will be forced on anyone. The Highways Agency says that any concern about the physical condition of routes to be detrunked is ill- founded, pointing to the last National Roads Maintenance Condition Survey which indicates that the state of non-core trunk roads is better than the average local road.
On the subject of money, there will be 'real and transparent funding for detrunked roads for three years', according to Dorset County Council's Guy Spencer.
Spencer is the CSS's expert on detrunking. 'After three years, the picture becomes blurred,' he says. 'A comprehensive review is under way of how local authorities are financed by central government and current spending arrangements could change fundamentally.'
Transfer of responsibility has to be at mutually convenient times, the Highways Agency says. The majority of roads are likely to change hands between next year and 2004, although a steady amount of detrunking is already under way. Nearly 100km of trunk roads will have had their status changed by 31 March, the end of this financial year.
Finally, a system of 'virtual detrunking' will be used for those roads where transfer of responsibility in the near future is legally impossible, for instance because of Super Agency contracts, or impractical because of current or planned improvement works.
At its most simple, a virtually detrunked road will become nominally the responsibility of the local authority for planning purposes, but remain the Highways Agency's responsibility for practical purposes, until the impediment to actual detrunking no longer exists.
'Government has gone a long way to meeting local authorities'
concerns particularly over the proper transfer of funds. A few may have worries over long term funding even so,' says Spencer. 'That said, the bulk should be content to accept their new responsibilities following more detailed discussions with the Highways Agency.'