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Chapter 11. Environmental challenges to the programmer's quest to optimise a motorway's route

Volume 1 Part 4
Brief résumé of Chapter 11:
Environmental challenges to the programmer's quest to optimise a motorway's route

W.E. Gallagher BSc, CEng, MICE, MIHT
formerly Director, London Regional Office
previously Head of Highways Computing
and Director Transport, South West Region, Department of Transport

Robert C. D. Baldwin BA, MLitt, MRIN, FLS
Hon. Secretary Motorway Archive Trust

This chapter in considering the way detailed decisions were informed and taken has necessarily analysed various technical and safety factors about curvature alongside considerations arising more locally from study of the landscape, archaeology and the essential character of settlements. It reveals why there is significant difference in the planning of routes through urban and rural contexts and the care taken in formulating manuals of best practice as well as the care taken to observe changing legal requirements. Its focus is on the search for the optimum route often identifiable on cost and construction grounds through the programmers’ endeavours, and why the best way of allowing for a variety of environmental factors inevitably resulted in compromises. The nature of public concern and the form of ministerial decisions on the advice of a public inquiry have changed as computerisation has allowed alternative routes to be quickly appraised, rendering suggestions of alternative routes worthwhile, and far from the blocking move some objectors had envisaged.

Back in the late 1960s practicable technology informing the route and form of a motorway promised to identify the lowest cost route and alignment, while the best cost-benefit return would be identified by comparing data derived from new Area Traffic studies. The most detailed of these was the two volume West Midlands Transport Study undertaken for local West Midlands authorities, the Ministries of Transport and Housing and Local Government and local transport organisations by Freeman, Fox Wilbur Smith Associates. Planners were soon to learn that even such detailed work and their putative spider networks used to identify busy routes markedly underestimated the policy implications of factors which were not easily quantifiable but were readily exploitable by those who wanted to oppose expansion of the motorway system. Nowadays, the development of a new programme would probably start with a formal systems development approach, commencing with defining the likelihood of politically sensitive problems associated with alternative routes, especially those arising from the area's natural history and archaeology, followed by a careful analysis of all the available options and leading to the selection of a working method. However, in the late 1960s most of the early developments in highways optimisation models were based on the application of one or other of the mathematical programming solutions then available to assist the engineer in finding a more cost effective design, not a route. This meant that the engineer remained pro-active during the operation, with plenty of interpretative work to do. For example, he might need to translate an alignment presented as a series of inter-connected points into an acceptable curvilinear alignment involving a certain element of de-optimisation. The case for seeking to optimise such a route was made by Dr V Calogero in his 1968 paper. (See chapter 3 of Volume II).

On 27th June 1969 a Committee of the Directors of all the RCUs agreed a brief to study their use of engineering resources. It would result in 1970 in the Engineering Committee producing a work popularly known as the "Pink Book" but entitled "A Report on Engineering Resources and Allied Subjects". After dealing in detail with the stages of soils research and topographical survey this showed the design stage of a road scheme would engage 87.5% of the overall resources required for road design (as opposed to bridge design) and 60% of the overall time. "Overall" meant here the entire time between the announcement of a scheme as in the preparation poll to its completion. Its figures (at C19) would show the potential for the application of computerised methodology because the Committee identified that the resource demand in staff of the first four elements in the costing of such roads was as follows:

Cost parameters for Road Design within the RCUs
- figures as expected by the date of issue, 1970.

Phase of work in progress

% of overall cost

Preliminary work on 1:10,560 plans.

2.5

Geological and Soil Survey work plus Topographical Survey and Surveyors' subsequent construction control.

12.5

Preparation and submission of firm programme report.

15.0

Preparation of Orders and land plans.

12.5

Design of the road and its drainage.

30.0

Final design of the scheme, including preparation of the contract documents, drawings and works estimates.

15.0

Supplementary works and tender procedure.

12.5

Total

100.0