Transportation network applications Chapter | 16 183different means of transportation that interconnect the zones. Multiple edges
may connect the same two nodes, corresponding to different means of trans-
portation. The flows of people or products generated per period are numbers
associated with the origin node and the same holds for the flows that arrive at
a destination node. The flows are transferred from the origin to the destination
node following paths, comprising the network’s edges. The capacity of an edge
denotes the maximum flow that can be transported through an edge at a certain
time period.
Most of the applications that support network-operation and network-
optimization decisions employ the network representation described earlier.
For better decisions, they add many more features to the network such as the
traversal cost for an edge—if it is fixed- or a function that computes the tra-
versal cost based on the actual load and the edge capacity. The traversal cost
is mainly the time needed to cross the edge, but it can also be the distance
to cover, or the estimated-fuel cost or the overall cost in money. For exam-
ple, sea-transportation networks assume different paths for moving from one
port to another, which may include naval zones of different traversal cost,
depending on the fuel type they allow to be used while moving within them
(Życzkowski, 2017; Fagerholt et al., 2015). Similarly, in a road-transportation
network, we may consider a different cost when moving between two cities
using a toll highway and a toll-free road, when crossing a city during peak or
off-peak hours, etc.
When we examine the network operation applications we may divide them
into two main subcategories–(1) applications that assist in monitoring the trans-
portation network and optimizing its usage by solving or preventing emerging
issues, for example, reducing traffic, responding to a sudden event by rerout-
ing traffic, etc., (2) applications that assist industrial stakeholders in the trans-
portation domain, for example, fleet monitoring and optimization applications,
freight transport logistics, etc.
The main concept behind both applications is to combine the network model
information with actual usage data from the networking monitoring system, and
then use the appropriate algorithms and models to recommend the path/route
for each transportation task that will optimize the network usage. In a long-term
usage scenario, the applications may recommend changes in the network that
will facilitate the above algorithms and will optimize network performance in
most conditions.
16.2.2.1 Product transport and logistics
The use of intelligent transportation systems in the logistics and freight trans-
port industry spans across different (multimodal) transportation networks (rail,
automotive, sea, and air) and combines real data with simulations in order to
minimize the idle time of the company fleet and products and maximize the flow
of goods over the multimodal network (Monios & Bergqvist, 2017). The combi-
nation of GPS data and data concerning the vehicle and its load condition allows