PEDESTRIANS and cyclists wanting get from St Ives to the Fen Drayton Lakes nature reserve will have a to make a detour of several miles from next month. After work for the Huntingdon-Cambridge guided bus starts in May, the old railway viaduct over the Gre

PEDESTRIANS and cyclists wanting get from St Ives to the Fen Drayton Lakes nature reserve will have a to make a detour of several miles from next month.

After work for the Huntingdon-Cambridge guided bus starts in May, the old railway viaduct over the Great Ouse will be closed to the public until the busway officially opens in February, 2009.

The scheme's promoters, Cambridgeshire County Council, strongly deny that construction of the busway will disadvantage walkers, cyclists and naturalists. It points out that they are not officially allowed on the viaduct at the moment, so its closure will not withdraw any rights from them.

Technically, the council is right. Arguably, by using the viaduct they have for years been "trespassing on the railway" (a specific offence under railway by-laws since the 19th century). But neither the police nor the structure's owners - successively, British Rail, Railtrack, Network Rail and now the county council - have until this year sought to challenge their right to be there.

CCC points out that, far from taking away a right of way, installation of the busway will actually create one. But work on strengthening the substructure of the bridge, installing new decking and laying the concrete guideway, which starts next month, will create safety hazards to which the public cannot be exposed.

Alongside the new guideway for the buses will be a new public bridleway for horse and cycle riders and pedestrians.

"There's no right of way there at the moment," a spokesman said. "We shall be creating one. We are going to provide something that really doesn't exist now."

To access the nine former gravel pits that have become the lakes' wildlife haven, travellers from St Ives will have to go by way of bridleways and footpaths from Fenstanton or Fen Drayton. There is a car park in Fen Drayton close to the old St Ives-Cambridge railway line, which runs through the middle of the area.