Transcript CIVITAS ELAN

Transport Appraisal – what it
is and why we do it
Tom Rye, Professor of Transport Policy
and Mobility Management
Transport Research Institute
Edinburgh Napier University
Session objectives

To consider why we need to appraise
in transport

To explain in brief some
methodologies and look at some
examples

To consider the political benefits of
appraisal

To understand scenario planning

To develop our own appraisal
framework
Why appraise?

When you buy a new house – do you just buy the
first one you see?

Factors you might take into account:
• Size
• Location
• …..

Maximise benefits of the house within a given
budget

Benefits/attributes of house - not same for all
people
• Near public transport
• Near a school
• Has swimming pool
Transport – similar

More projects exist than money to fund them

Need some way to choose between them

Maximise benefits we get for money spent

Achieve objectives

Give taxpayer value for money

(May) make decision-making transparent

Can make decisions easier to defend

May make projects more “thought-through” – so
more effective/higher quality

BUT – we cannot see the project before we buy
it – so we have to PREDICT its impacts
Choosing which tram line to build
Some different methods
of appraisal
Cost Benefit Analysis 1

You are considering converting a freightonly railway line in suburban Ljubljana to
S-Bahn operation with new stations and a
train every 15 minutes.

What would be the benefits and costs?
• Benefits
• Costs
Cost benefit analysis 2

When you have predicted all benefits and
costs for the scheme for years into the
future… (requires modelling…)

Change them into a common unit (€€€€)

Add them up

Subtract costs from benefits

Result, or ratio – shows value of scheme

Example – German Standardised
Assessment for Infrastructure Investment

Any problems with this method?
Objectives-based appraisal

Set a number of agreed objectives

Assess scheme’s performance in
relation to these

Do not have to all be in money
form

Example of this system – UK
WebTAG www.webtag.org.uk

See also sheets handed out

Any problems with this method that
you can see?
Multi-criteria analysis

As objectives-based appraisal, but then:
• Score performance of scheme against
objectives
• Weight objectives
• Calculate overall score for each
scheme
• Fund schemes with best score – or
those delivering most score per € spent

Examples:
• Many local authorities, UK (local safety
schemes)
• Swiss Cantons e.g. Canton Zuerich
Key requirements for appraisal

Agreement on benefits and costs, or
objectives, to include in appraisal

Monetary values of costs and benefits (for
CBA)

Weightings for objectives (for MCA)

For larger, longer term schemes – a
model

Indicators e.g. total accidents; or a rate?

But…

Size of appraisal should relate to size of
scheme
How to use appraisal in decision-making

Decisions about new schemes – always
political

Appraisal can aid political decisions,
though – can makes it easier for politicians
to say:
• We have taken everyone‘s needs into account
• We have looked at many different options, and
this one is the best
• This new railway is excellent value for money
• Our new system of traffic calming will save XXX
lives a year
• The new busway/road/bikeway/MM scheme will
bring €3 of benefits to Ljubljana for every €1 we
have spent on it
• This scheme achieves our objectives