Transport, Travel and SHS Data

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Transport, Travel and SHS Data

• SHS Topic Report Modal Shift

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SHS Topic Report Modal Shift

• Aims of the research are
• summarise key statistics on current mode choice
  and perceptions of alternative modes
• Identify factors which affect behaviour of
  travellers in making mode choice.
• The topic report will cover
• Car Ownership
• Car vs Public Transport
• Motorised vs Non Motorised Modes
• Travel to School

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SHS Topic Report. Background

• Traffic and congestion are growing. This has
  implications for economic, environmental and
  social costs, including longer journey times for
  people and products, reduced air quality, road
  accidents, impacts on health and contribution to
  climate change.
• The Scottish Executive recognises that more needs
  to be done to encourage modal shift.
• Scottish Household Survey data shows that among
  those who travel to work by car, 47 could use
  PT, but choose not to. The main reasons are
  Inconvenience, journeys take too long, lack of
  direct routes, the need to have a car at work and
  the cost.

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Car Ownership

• Travel Diary Data (1999 to April 2003) shows car
  mode share is
• 20 from non-car owning household
• 76 from households with one car
• 86 from households with two or more cars
• Using the SHS data it is possible to define car
  ownership in three ways
• Household Car Ownership
• Car competition between adults in household
• Car competition between licence holders in the
  household
• The two forms of car competition, Adults versus
  car gives a better (i.e. wider) partition than
  Licence holders versus cars, but neither are
  significantly different from the simple car
  ownership (C0, C1 and C2) partition.

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Car Versus PT

• The attitudes and attributes of travellers with a
  realistic choice exists are key to understanding
  and explaining car vs PT mode choice
• Our approach is to identify the set of SHS
  Travel Diary journeys where there is a
  realistic choice. This combines the following
  data
• Distance from nearest bus stop (SHS data)
• Journey length (SHS data)
• Car ownership (SHS data)
• Car/PT Generalised costs (TMfS)
• Parking charges by journey purpose (TMfS)

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Car versus Public Transport

• A relative cost variable (PT/Car generalised
  cost) has been attached to each record in the
  travel diary data set
• PT Generalised costs include
• walk time,
• effective wait time,
• in vehicle run time,
• boarding/transfer penalties,
• fares
• Car Generalised costs include
• in-vehicle time,
• Vehicle Operating Costs (fuel and non-fuel) and
• tolls

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Car Versus Public Transport

• The extended SHS Travel Diary data set would be
  partitioned on the basis of variables strongly
  correlated with mode choice.
• CHAID will be used (Chi Squared Automatic
  Interaction Detection)
• Partition could include
• Car ownership
• Relative cost of PT
• Purpose
• Age
• Income
• Day of week.

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Non-Motorised Modes

• Analysis will focus on short trip lengths where
  walking and cycling offer significant alternative
  modes

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Non-Motorised Modes

• CHAID analysis will partition the set of short
  trips.
• Variables expected to be included in the
  partition are
• Car ownership
• Age
• Day of week
• Month (surrogate for weather effects) and
• Journey purpose.

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Travel to School

• Travel to School is an important area of cross
  cutting policy research involving education,
  health, environmental, road safety and transport.
  
• It has been estimated that one in five cars in
  the AM week day peak is taking children to school
• SSTAG (Scottish Schools Travel Advisory Group) is
  already carrying out research on mode choice for
  trips to school
• The SHS data provides a number of questions about
  the usual means of travel to school, reasons for
  choosing this mode and availability of public
  transport.

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Other recent uses of SHS data

• CEC Land Use and Transport Interaction Model (CEC
  LUTI)
• Return home proportions by time of day
• Cycling and Walking demand matrices
• Trip lengths by journey purpose
• Analysis of simple tours.
• Transport Model for Scotland (TMfS)
• Inputs into the demand matrices (mode purpose
  time for HB/NHB trips)