66 Highway Engineering
In addition, a table listing the existing uses of land to be taken and a quan-
tification of the specific areas required for the proposal should be included,
together with a mitigation table listing the measures such as noise barriers, inter-
ceptors, balancing ponds and even local re-alignments proposed by the devel-
oper to minimise environmental impact.3.6 The new approach to appraisal (NATA),
During the late 1990s, the UK government reviewed its road programme in
England and identified those strategically important schemes capable of being
started within the short to medium term and listed them as potential candidates
for inclusion within a targeted programme.
Each of these schemes was subject to a new form of assessment that incor-
porated both the COBA-based economic appraisal and the EIT-based environ-
mental assessment. This methodology, called the new approach to appraisal
(NATA), includes a one-page summary of the impacts for each of the projects
considered. Within the method, all significant impacts should be measured.
Wherever possible, assessments should reflect the numbers affected in addition
to the impact on each. It is desirable that all impacts be measurable in quanti-
tative terms, though this may not always be feasible.
This appraisal summary table (AST) is designed for presentation to those
decision-makers charged with determining whether approval for construction
should be granted, and if so what level of priority should be assigned to it.
It thus constitutes a key input into the process of scheme approval and
prioritisation.
The AST summarises the assessment of the scheme in question against the
following five objectives and their constituent impacts, seen by the government
as being central to transport policy: Environmental impactNoise, air impacts, landscape, biodiversity, heritage
and water
Safety
Economy Journey times, cost, journey time reliability, regeneration
AccessibilityPedestrians, access to public transport, community severance
Integration.Environment
Noise
The impact of noise is quantified in terms of the number of properties whose
noise levels in the year in question for the ‘with proposal’ option are greater or
less than those in the base year. Given that only those properties subject to noise
increases of greater than 3 dB(A) are taken into account, the following quanti-
ties must be derived: