Lec 20, Ch.11: Transportation Planning Process objectives

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Lec 20, Ch.11 Transportation Planning Process
(objectives)

• Understand how decisions to build transportation
  facilities are made
• Understand basic elements of the transportation
  planning process
• Understand basic elements of travel forecasting
  (This topic will be discussed in detail in CE565,
  winter semester. CE361 is the only prerequisite
  for CE565 according to the course catalog, but I
  recommend you to take CE370 (old) or CE470 (new)
  before you enroll in CE565.)

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What we cover in class today

• Basic elements of transportation planning (This
  concept applies to any transportation planning
  including urban transportation planning,
  pp.509-514)
• Urban transportation forecasting process
• Four-step travel demand forecasting A general
  introduction

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The transportation planning process

• It has become institutionalized, meaning
  federal guide guidelines, regulations, and
  requirements for local planning are often driving
  forces behind existing planning methods. Have you
  heard of MPOs (metropolitan planning
  organizations) like the Mountain Land of
  Governments or the Wasatch Front Regional
  Council? Or, have you heard of Envision Utah?
• It is intended to furnish unbiased information
  about the effects that the proposed
  transportation project will have on the community
  and on its expected users.
• It is intended to give the appropriate
  information to those who will be responsible for
  deciding whether the transportation project
  should go forward.

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Basic elements of transportation planning
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Example 11-1 Planning the relocation of a rural
road (simple, yet good enough to explain the
steps)

• Step 1 Situation definition
• to understand the situation that gave rise to
  the perceived need for a transportation
  improvement

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Step 2 Problem definition
Purpose of the step Describe the problem in
terms of the objectives to be accomplished and
translate those objectives into criteria.

• Example
• Objective Statements of purpose Reduce
  traffic congestion, Improve safety, Maximize net
  highway-user benefits, etc.
• Criteria Measures of effectiveness Travel
  time, accident rate, delays (interested in
  reductions in these MOEs)

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Step 3 Search for solutions
Brainstorm options at this stage.
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Step 4 Analysis of performance

• Estimate how each of the proposed alternatives
  would perform under present and future conditions.

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Step 4 (cont) Ranking of alternatives (in terms
of MOE)
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Step 5 Evaluation of alternatives

• Determine how well each alternative will achieve
  the objectives of the project as defined by the
  criteria.

Cost-wise best
This is a multi-objective evaluation problem.
Improvement-wise superior
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Step 6 Choice of project

• Based on the alternative evaluation in Step 5,
  we will choose the best alternative for design
  and eventual construction. The best choice may
  not be built because of opposition by the people
  of the community that is affected.

Step 7 Specification and construction

• Once the project has been chosen, a detailed
  design phase is begun, in which each of the
  components of the facility is specified.

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Urban transportation (demand) forecasting process

• This task is a technical effort to analyze the
  performance of various alternatives. We must
  define the study area first. Then further
  subdivide the area into traffic (analysis) zone,
  TAZ, for data tabulation and analysis.

• Homogeneous socioeconomic characteristics e.g.,
  high-income residential
• Minimum intra-zonal trips
• Use of physical, political, and historical
  boundaries, where possible
• Zones, once created, should not be subdivided
  into smaller zones during analysis
• Zones generating and attracting approximately
  equal trips, households, population, or area
• Use of census tract boundaries, where possible
  (easier to collect data from the Census Bureaus
  publications)

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Travel demand model flowchart
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Four basic elements of the urban transportation
forecasting process
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Analysis zones for transportation study (TAZ)
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Link-node map for highway system

• Link-node maps are the starting point for the
  4-step transportation demand forecasting process

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4-step transportation demand forecasting process

• Preparation population and economic analysis and
  land use analysis

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Graphical way of understanding the 4-step demand
forecasting process
200 trips from zone 46 to zone 29
1000 trips attracted
1000 trips generated
70 this route
Auto total 95
Public transit 5
25 this route