01 - Network Design - PT

Management and planning

planning

Planning is to optimise the different elements of a system in order to achieve the optimum output.

Quantify the potential effect of deploying a system.

Planning is a rational process from the system's analysis anbd understanding its behaviour, allocates resources effectively in order to reach a target in a future scenario.

Mobility mutations

Infrastructure --> services
- I don't care what infrastructure you need, I care about what service you want to provide, then we pick what infrastructure is best
Objects --> processes
Static --> dynamic
- For example distinguish between pick hour and other times
Recurrence (pendular trip, commuter) --> singularity
Infrastructures for people
Re-engineering mobility
Information on-line, positioning and tracking

Urban Planning and economic territory

Usually more density results in higher service.

Population density is one of the most important parameter that rules PT planning.

Transportation system

Core elements:

Engine - power drain
Container - provide protection and carriage
Control
Infrastructure way
But there are many other parts in a transportation system:
Stakeholders
Society
Technology
Culture
Business
Environment
Energy

drt gone wrong example - kutsuplus

Kutsuplus: One of the first attempt to provide DRT in a big city (Helsinki). It was very well planned, people liked... In the end, the average cost per trip for the bus operator was 18 €/trip (= €/pax). In Barcelona, a bus trip is 2.65 €/pax (we're basically talking of the ticket). For a taxi is 12 €/trip. A taxi in Barcelona is cheaper than a trip with DRT in Helsinki.

Public transport decalogue

Minimal demand treshold (Bus is efficient if demand is lower than 6000 pax/h. Tram - 6000-20000 pax/h)
Investment + operation + maintenance cost
- We need to take into account all costs
Minimal frequency and service time period
Adequate stations
Door-to-door chain
- All the means of transportation needed to move from the initial starting point to the final destination
Information, readability
Time competitive

%%🖋 Edit in Excalidraw%%

For bus, since you can leverage existing infrastructure, you start from a lower budget.

$τ$ is the fare

Demand	Cost	Freq	Income
$D_{0}$	$C_{0}$	$F_{0}$	$D_{0} τ_{0}$
$D_{1}$	$C_{1}$	$F_{1}$	$D_{1} τ_{1}$
If I want to reduce cost I can take different routes:

Subsidies
Tolls
Reduce frequency

Reducing frequency will reduce service and therefore reduce demand. Also cost will probably be reduces:

$D_{1} < D_{0}$
$C_{1} < C_{0}$
$F_{1} < F_{0}$
$D_{1} τ_{1} < D_{0} τ_{0}$

If demand for bus reduces even more in favour of private cars, then we create even more problems:

More congestion
Travel time on bus will go up
Operation cost of the bus will also go up

This process is known as the vicious cycle of PT. To avoid this, every PT service has to be operated over a minimum service threshold.

Time perception

It's easy to capture the door to door travel time. But what counts is the perceived travel time

Access and waiting time are perceived 2/3 times more than travel times
Transfers are perceived 3 to 4 times more than travel times

Main advantages of rail transit are right of way and capacity. In urban environment, the less friction is not really relevant since there are many stops.

Smart ICT in mobility

It's important to keep in mind cause-effect relationship.

Transport microeconomics

Let the total cost be

T C = \sum_{i} I_{i}

sum of all the investemnts.
Let $x$ be the demand.

Then we define average cost

Average cost

average cost ($c_{av}$)

$C_{a v} = \frac{C T}{x}$

and Marginal Cost

Marginal cost

marginal cost ($c_{ma}$)

$C_{m a} = \frac{\partial C T}{\partial x}$

Marginal cost in road network is higher than the average cost. In PT is lower.

Moggridge paradox