Enhanced analytical decision support tools The Scheme level

1
Enhanced analytical decision support tools The
Scheme level

• Final workshop of the DISTILLATE programme
• Great Minster House, London
• Tuesday 22nd January 2008
• Dr Simon Shepherd
• ITS, University of Leeds

2
Objectives

• To enhance existing predictive models to
  represent a wider range of policy instruments
• To improve the ability of users to apply models

3
Suggested Themes
1. Demand restraint measures 2. Public transport
improvements 3. Land use measures 4. Soft
measures (attitudinal) 5. Slow modes and small
scheme impacts 6. Data issues 7. Model use
4
Demand restraint modelling

• Cordon location short cut approach
• Area based charging
• Parking choice model

5
Cordon Location Problem
6
Top 15 links high marginal cost tolls
7
A short cut approach

• Aim to develop a method between judgement and GA
  based approach
• Use fact that Top 15 MC tolls gave high
  proportion of first best benefits
• Charge a high cost trip somewhere not
  necessarily on the high cost links
• Use SLA to design where best to place cordon and
  catch the high cost flows

8
Display SLA using bandwidths
9
Summary cordon location

• Proven for networks of Cambridge, York, Leeds and
  Edinburgh
• Adapted for simulation networks of Shrewsbury and
  Cambridge
• Approach included in DfT webtag advice
• Now being used on Nottingham network

10
Area based charging

• Adapt models to charge for trips within an area
  rather than per crossing of a cordon
• Allow exemptions or discounts for residents
• Implemented in SATURN
• Tested on a Cambridge network

11
Example for a given cordon
12
Area based charging benefit surface
13
Parking model - Aims

• Develop a simple parking location choice model
  with the demand spread over multiple time periods
• Integrate within assignment stage of the
  transport modelling process
• Develop a modelling framework that can be used to
  test parking demand management policies
• Illustrate the method with practically available
  data for a realistic network of Leeds

14
Implemented for Leeds SATURN model
Car park 2
Car park 1
15
Parking summary

• Car park choice for multiple user classes and
  across time periods has been incorporated within
  an equilibrium assignment approach (matching Lam
  et al)
• Impact of car park pricing structures/capacity
  can be modelled with the approach
• Further possible extensions departure time
  choice, elastic demand, etc.

16
Improved Public transport modelling

1. DRACULA Bus reliability
2. STM Partial modelling of Trip chaining (extended
   park and ride)

17
DRACULA Bus reliability

• Incorporates interactions between bus operation,
  passenger arrivals, boarding times and private
  traffic.
• Simulation helps understand impacts on
  reliability and tested alternatives to increase
  reliability
• York case study

18
The DRACULA model of Route 4

• The bus route in red
• DRACULA model
• 138 junctions (39 signalised)
• 260 links
• 21 bus stops
• 2 bus lanes

19
Results of model validation

• Ten simulation runs, over a period of 1.5 hours,
  12 services each run
• Modelled average journey times correspond well
  with observation
• Model correctly predicting journey time delays at
  the key sections en-route

20
Summary of results

• Headway variation and number of passengers
  boarding interrelated
• Unreliability increases with congestion and
  passenger demand
• Passenger demand has more serious impact on
  headway variability than on total journey time
• Extension of bus-lane itself does not improve
  reliability, but combined with signal gating
  strategy will bring benefit
• Reduced boarding time (advanced ticketing system)
  brings in most significant improvements

21
STM Park and Ride

• Treats trip chaining in terms of park and ride at
  Glasgow underground stations (Subway system). The
  entire Subway system can be modelled.
• Uses model of capacity constraint including
  overflow model to transfer excess demand at car
  parks.
• Used to investigate interaction between direct
  travel to Glasgow centre and by Subway park and
  ride in context of strategic model.

22
Subway choice sets

• Additional program used to generate viable
  Subways for choice for each OD movement.
• Based on routes for direct travel
• Currently up to 5 Subways possible ( a middle
  possibility and 2 side alternatives)

23
Subway catchment zones
Subway catchment area (blue) and mode shares for
this
24
Run I (50 increase in jobs) impact on Subway
system
mode share increases for all the catchment
zones Subway increases by about 16
25
QUESTIONS?

• Contact Dr Simon Shepherd
• Institute for Transport Studies
• University of Leeds
• S.P.Shepherd_at_its.leeds.ac.uk
• Tel [phone]