Appunti di lezione Transport Planning

TRANSPORT PLANNING

The focus of the planning activity is on the question "should we do...?"

MANAGERIAL PERSPECTIVE The real challenge is to take the right decisions in the transportation sector.

• The transport system is composed by two main elements:
  • - The travel demand = need of people performing different activities in different places
  • - The transport supply = infrastructures and transport services that can satisfy the travel demand

FLOWS represent the interaction between travel demand and transportation supply ➔ transport planning has to deal with congestion.

In fact, transportation systems have a certain capacity. After this value of flow, the price increases without the increasing of quantities (flows).

• Congestion problems mainly concern urban areas, and worsened in 20s and 30s of XX century with the expansion of cars as means of transport affordable by the majority of the middle class ➔ Henry Ford in the USA. In Europe, regimes promoted the common use of cars and, at the same time, the construction of infrastructures.

[Supply-side policy but without any planning] + [economic boom in the '50] ➔ [mass motorization and congestion]

TRANSPORT PLANNING

The focus of the planning activity is on the question "should we do...?"

MANAGERIAL PERSPECTIVE. The real challenge is to take the right decisions in the transportation sector.

• The transport system is composed by two main elements:
  • The travel demand = need of people performing different activities in different places
  • The transport supply = infrastructures and transport services that can satisfy the travel demand

Engineers need to apply economics principles, according to the micro-economics.

FLOWS represent the interaction between travel demand and transportation supply. Transport planning has to deal with CONGESTION.

In fact, transportation systems have a certain capacity. After this value of flow, the price increases without the increasing of quantities (flows).

• Congestion problems mainly concern urban areas, and worsened in 20s and 30s of xx century with the expansion of cars, as mean of transport affordable by the majority of the middle class. Henry Ford: in the USA. In Europe, regimes promoted the common use of cars and, at the same time, the construction of infrastructures.

[ Supply-side policy ] but without any planning ] + [ economic boom in the '50 ] [ mass motorization and congestion ]

1. In the USA during the '50 as many cars were stucked in the traffic, a lot of multi-lane roads were built but this "solution" did not solve the congestion, but worsened the situation: both the demand and supply were moved to the right.

   • Necessity of TRANSPORT PLANNING, according to the principle "predict and provide" ( = predict flows and consequently provide the infrastructures), in opposition to the "supply-side reactive policy". Forecasting substitutes reacting
   • In Detroit and Chicago, the first transport plans were made during the '50, sponsored by public administrations and private cars producers (eg: General Motors)

2. In the '70 economic crisis due to the oil shock. Also the transportation sector had to change paradigm, adopting the so-called demand-side planning policy ( = action on the demand curve).

   • a. Limitation of the travel demand
   • b. Multi-modal perspective substitutes car-centered vision
   • Need to contain the consumption of energy (oil crisis) there is the need to redirect the demand to more energy efficient means of transport.

3. In the '90s environmental concerns. An even stronger is put on alternatives to cars ➔ Travel demand management strategies.

   • For these reasons: Transport planning necessity.

TRANSPORT PLANNING PROCESS

- Scientifically based (theory + empirical facts)

1. Based on data: surveying activity

   1. Make observations and gather data on travel demand and supply

   2. Organise the data in a meaningful way

NB: Flows are not sufficient to describe the travel demand, because they don't allow to know the O/D data, but only the data along a certain section. So, we have to distinguish:

• TRAVEL DEMAND

  • WORKSHOP 1, 2, 3 - zoning: O/D
  • Dividing the study area in traffic analysis zones using centroids

In this way it is possible to represent the ORIGIN-DESTINATION