The facts
Location: A5036 Liverpool
Clients: Highways Agency
Start / completion dates: April 2006 -
November 2006
Services provided: Preliminary design,
traffic assessments , environmental appraisal, economic appraisal,
traffic modelling
The project
The A5036(T) provides the main access into the Port of
Liverpool from the motorway network.
The road is urban in character and a number of junctions are
currently over capacity during peak periods. Capita
Symonds was commissioned to appraise a single carriageway
improvement scheme running parallel to the existing route. The
scheme would improve journey times and journey time reliability to
the Port, and provide environmental benefits through traffic
reductions on the A5036. The transport modelling work comprise two
separate elements described below:
Three separate scheme options were developed and modelled using
an existing SATURN highway assignment model that had
been developed to assess a nearby local authority scheme.
Traffic forecast for opening and design years were developed
incorporating proposed developments, with overall growth
constrained to TEMPRO forecast
growth. An assessment of variable demand was then
carried out using DIADEM.
An economic appraisal of the scheme was then
carried out using TUBA. The impact of the options on maintenance
and construction delay was determined using QUADRO.
A separate COBA assessment was carried
out to determine accidents impacts. The results of the
economic appraisal were then combined with the environment,
integration and accessibility appraisals in Appraisal Summary
Tables.
Due to its impact on the Port of Liverpool,
the scheme was eligible to apply for entry into the Department for
Transport’s Transport Innovation Fund. Capita Symonds therefore
carried out a quantitative assessment of the benefits that the
scheme would provide to the UK’s Gross Domestic Product
(GDP).
The work was carried out using the methodology
set out in the DfT report, Transport, Wider Economic Benefits and
Impact on GDP”. Issues addressed included agglomeration
economics, increased competition, imperfectly competitive
markets and improved labour supply. The assessment
demonstrated that the scheme provided significant welfare and GDP
benefits not taken into account in a traditional economic
appraisal.