Highway Engineering

Scheme Appraisal for Highway Projects 71

land use and transportation plans and policies at local, regional and national

level. A three-point textual scale (neutral-beneficial-adverse) is used:


 Beneficial– more policies are facilitated than hindered by the construction

of the proposal


 Adverse– more policies are hindered than facilitated by the construction of

the proposal


 Neutral– the net effect on policies is zero.

This assessment is intended to be broad-brush in approach, with marginal

changes ignored.

The AST framework is summarised in Table 3.8.

Criterion Subcriterion Quantitative measure Assessment

Environment Noise Number of properties Net number of properties

experiencing: who win with scheme

• An increase in noise levels
  •A decrease in noise levels
  Local air quality Number of properties PM 10 score
  experiencing: NO 2 score


• Improved air quality
  •Worse air quality
  Landscape — AST 7-point scale
  Biodiversity — AST 7-point scale
  Heritage — AST 7-point scale
  Water — AST 7-point scale
  Safety Number of deaths, serious Present value of the benefits
  injuries and slight injuries (PVB) due to accident
  reductions (£m)
  Economy Journey times — Present value of the benefits
  and VOCs (PVB) due to journey time and
  vehicle operating cost savings
  (£m)
  Cost — Present value of the costs
  (PVC) of construction (£m)
  Reliability % stress before and after Four-point scale
  project implementation Large/Moderate/Slight/Neutral
  Regeneration Does proposal serve a
  regeneration priority area? Yes/no
  Does regeneration depend on
  the construction of the
  proposal?
  Accessibility Pedestrians, etc. — AST 7-point scale
  Public transport — AST 7-point scale
  Severance — AST 7-point scale
  Integration Consistent with implementation
  of local/regional/national Beneficial/Neutral/Adverse
  development plans

Table 3.8Framework for appraisal summary table