Summary Report

5. The Orbital Option

Key Elements of the Orbital Option

  • New highway through the south-east of the built up area connecting the M11 with the A14 to complete the orbital around Cambridge
  • Tunnel to preserve the visual connection between the Gog Magog Hills and the City
  • Short tunnel under Shelford Road
  • Two new bridges over the railway to the south (London Line) and to the east (Newmarket line)
  • The new highway would form the boundary of the new developments at Clay Farm and Addenbrookes Hospital in the south the Airport in the east

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Sustainability implications

The economic efficiency of the Orbital Option is high as it makes a larger supply of dwellings and business floorspace accessible, therefore making the economy more competitive and thus reducing costs.

It is clearly noticeable that the City of Cambridge benefits more than the other districts as there is less upward pressure for salary increase and thus on the cost of living. This is reflected in lower pressure for salary increase and thus a reduction in the cost of production, which would help to maintain the competitiveness of the Sub-region.

It is estimated that exporters in the City would save about 75 million in annual costs of production. The overall savings for the Sub-region are estimated at 176 million per annum.

The results do not significantly alter the present social mix of the area. There is, however, a slight proportional increase in the South and East Cambs districts of higher income groups that may improve the social balance in those areas. Lower income groups also take advantage of the improved access to lower priced housing in the surrounding districts.

The benefits in terms of cost of living savings are reasonably distributed throughout all of the socio-economic groups. However, the middle income group SEG2 clerical and administrative receive more benefits, as they are able to take advantage of the reduction in costs in South Cambs and Cambridge City where they are concentrated.

From an environmental point of view, the Orbital Option produces mixed results. On the one hand, there is a slight reduction in car traffic within Cambridge with the consequent increase in average speeds and reduction in emissions. On the other hand, there is an increase in car travel in the Sub-region that negates the reduction within the City. The overall impact on fuel consumption and carbon emissions is 16% higher than the Base Case.

The visual impact of the orbital around the south east of Cambridge can be reduced by the construction of a 1.5km tunnel through Missleton Hill between Worts Causeway and Fulbourn Road, thus minimising the disturbance to the natural landscape of the Gog Magog Hills, south east of Cambridge.

The rest of the orbital to the south and east of Cambridge would have a minor impact of the landscape, as it will be on the edge of the development around Addenbrookes, at Clay Farm to the south, and round the airport to the east. The orbital would reduce congestion for traffic accessing Addenbrookes and would include a tunnel under Shelford, subject to a feasibility study of the ground conditions, with bridges over the railway lines to the south and east of the City.

Investment Costs Orbital highway 50
  Tunnel 80
  Link Road -10
  Total Costs 120
Annual Benefits User: tolls -
  User: cost savings 1.1
  User: time savings 6.4
  User: convenience 6
  User Total Benefits 13.5
  Operator: revenues -
  Operator: costs -
  Operator Total Benefits -
  Government Benefits 1.3
  Total Benefits 14.8
Rate of return Social 12.3
  Operator -


  • Car traffic reduces within Cambridge, but there will be more traffic around Cambridge
  • Public transport use does not change
  • Walking and Cycling reduces
  • Environmental negative impact on the south-east fringes of the City is mitigated by tunnels. Carbon emissions increase
  • Cost of living and production costs reduce making the Sub-region more competitive
  • Investment cost is moderate with a substantial economic benefit
Introducing the Study Base
Cycling/ Walking Public Transport Orbital Highway Congestion Charging Combined Option Options Compared