Generating Scheme Optionsand

Exploring Distributional Impacts

Final workshop of the DISTILLATE programme

Great Minster House, London

Tuesday 22nd January 2008

James Paskins

UCL

1

ObjectivesObjectives/Indicators

(7)

Assess problems (8)

Possible instruments (9)

Predict impacts (12)

Compare solutions (13)

Implement (15)

Evaluate performance (15)

Monitor (15)

Barriers (10)

Possible strategies (11)

Optimisation (14)

Appraisal (13)

Scenarios (11)

• To develop option generation methods• To enhance the range,

innovation and quality of options

• For strategies and schemes

Four Option Generation Products

Strategies Schemes

‘Inside’ the box

Packages of urban measures

[KonSULT]

Streetspace main road redesign

(Bloxwich)

‘Outside’ the box

Accessibility Planning options

(Barnsley Dearne)

Community space design

(Blackpool)

Facilitating Community Space DesignUsing Participatory GIS to generate options

Problem Features –What do people want to see changed?

Future Changes -What do people want to see happen?

Business-as-usual

Pedestrian priority

minor infrastructure improvements

Major changes to promote community use of the space

Out-of-the-Box Options• Participants were encouraged to consider and justify their suggestions• They were guided through this using flow chart• This helped to identify alternative ‘out-of-the-box’ solutions

For example:

What would you change?Improve the car park

How? More disabled bays and better signage

Why do you want this change?Improve safety of users

How else could you make the area feel safer? Stop the kids hanging around

How would you do to achieve this? Put in facilities for kids

• So a ‘solution’ to a ‘transport’ issue – might be better play facilities

Designing Streetspace Options

• Urban street design often causes major controversy – difficult to gain public support

• Conventionally engineers develop a preferred solution, which goes to consultation

• Little attention paid to options:– Which street design elements are included?– How many and when?– Where are they located?

The Tools: ‘Blocks’ & ‘Bytes’• For use in more complex streets, where

have many competing street user groups

• Two complementary techniques:– Physical design exercise with local

communities: scale plans, blocks, acetates– Conversion to electronic, GIS format, for use

in larger public meetings and for developing engineering drawings

Tool 1 - Blocks• By using blocks to scale, and detailed maps

of the high street:– Users are made aware of many of the component

options for allocating street space– They then generate their own options, by

combining blocks in different ways and locations– Maps to scale allow users to work within the

constraints that the engineers, face without having to have a detailed knowledge.

60mm

Example of Loading Bay Block

1:250

Blocks – Colour and Size

• Use of colour to denote different types of space usage

• Some of these based on current street colour categories, e.g. blue denotes disabled parking (blue badge)

Feature ColourVehicle Lane Grey

Bus Lane Red

Cycle Lane Green

General Parking Yellow

Disabled Parking Blue

Loading Brown

Bus Stop Orange

Traffic Island Cyan

Signal Crossing/Zebra Approach

Magenta

Street Element Design Options

• Based on a development of LineMap, a GIS based tool developed by Buchanan Computing to plot road markings

• The software plots all road markings from Traffic Signs Regulations and General Directions (TSRGD) 2002

• Now converts to/from the block format, and can be edited on screen

Tool 2 - Bytes

Conversion: Blocks -> Lines

Scheme Comparison

Display Bus on Bloxwich High Street

The display includes the full plan, information about red routes and a description of the planning process.

• Using scale blocks and maps makes the design process as simple as possible to understand, and highlights opportunities and constraints

• LineMap provides a bridge between outline design and professional drawings – suitable for use in larger public meetings for scheme editing

• Enables councils to regain confidence of local people and plan with a wider understanding of the needs of an area.

• Allows members of the public to participate in street design and encourages innovative solutions

• High level of public support for resulting scheme• Council very pleased with outcome – removes normal

confrontational approach• Walsall has purchased copies of both tools, and plans to

repeat in other parts of the Borough, where face major opposition

Conclusions

Identifying Distributional Impacts

Inputs

Impacts

Benefits MatrixThe impact calculations rely on a matrix that specifies whether a design element has a positive or negative impact for a particular user group

Fine Tuning the Comparisons• Weightings can be applied to– User groups– Street design elements– Individual user group/element pairs

• Adjusting the weights allows the comparison to reflect the relative importance of particular user groups or street design elements

• Values in the matrix can be adjusted to show the particular importance of a design element to a particular group – for instance, disabled parking bays for disabled drivers

Using Alternative Relationships• The default relationship between street

design element and impact is linear

• Different relationships, such as maximum provision and diminishing returns, can be applied to each street design element

Parking spaces

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A B C D E

Comparison area

Existing provision

Group 1 scheme

Group 2 scheme

Final scheme

Weighted versus Unweighted

• Diminishing impact of increasing parking provision

10% per space for reduction for increases above 20 spaces after 20 for all user groups

• Priority for bus users

A weight of 2 given to bus stops for all user groups • Representing the decreased usefulness of standard parking bays for

disabled car users

A weight of 0.5 given to standard parking spaces for disabled car users

The following sheet shows the results of two types of scheme comparison

1. Unweighted comparison

2. Comparison with the following weights and relationships:

Comparison of ImpactsStreet User Group Existing

provision (B)Group 1

scheme (C)Group2

scheme (D)Final

scheme (E)

Pedestrians

N/AComparison

Plan

0 0 0Pedestrians who have mobility difficulties

0 0 0

Those using the street to socialise/relax

0 0 0

Cyclists 0 0 0Bus users visiting the street -4 -2 0Those using the street as a link 0 0 0Car users (non-disabled) visiting the street

11.94 10.86 9.22

Disabled car users visiting the street 2.97 7.43 0.61

Shopkeepers 1 1 1

Unweighted Total 34 32 19

Total 11.91 17.29 10.83

Spreadsheet Conclusions

• The spreadsheet provides an objective and flexible framework for helping to compare different plan options

• Careful thought is required about the weightings and relationships that are chosen– Policy priorities– Usage patterns

• The spreadsheet fits in well with the option generation techniques that have been developed as part of DISTILLATE

Questions?

ContactProfessor Peter Jones

Centre for Transport Studies

peter.jones@ucl.ac.uk

Tel: 020 7679 0478

www.distillate.ac.uk