By O Kipps, Icos
This paper was first publsihed in GE’s July 1982 issue
The M25, London Orbital Road, a dual carriageway motorway which when complete around the year 1986 will be about 190km long completely encircling the metropolis, may claim to be un’:que in many ways, Out of this total length the 3km section running eastwards from the A10 Cambridge Road past Waltham Cross to the west bank of the River Lea Navigation has the distinction of being the most expensive section of road in Britain.
This section is currently under construction by Tarmac National Construction Ltd. for the Department of Transport, Eastern Road Construction Unit, under a £28.6M contract. Work commenced in 1980 and completion is due in 1983.
The line of this section runs through the heart of an existing residential area, where, for environmental reasons, the motorway is to be run underground through the biggest cut-and-cover tunnel currently under construction in this country (Fig. 1). This super-underpass, 670m long, will be known as the Holmesdale Tunnel.