IEEE Technology and Society Magazine - June 2019 - 29

one central station to another
central station has lost the justification of its existence....train
stations are not often in a close
proximity of the passenger, so
the passenger should use
another means of transport to
arrive at a train station whereas
when using driverless cars there
is no need for the hassle of
these connections" (p. 26).

This property would ensure
cheaper means of transport, includsmoothness in traffic flows and
ing those working in lower-paid occuat intersections to achieve the
pations, which are essential for the
urban economy. Furthermore, the lack of affordable
transport would restrict
employment opportunities,
especially for the less affluNew York City would need to serve
ent or for youth, further hamthe current 1.7 billion annual trips
pering the economy [8].
Overall, this situation could
made by the subway with access
point towards the need for
subsidies, that is, the situato driverless vehicles.
tion to which Wiseman
objected in the first place.
capacity gains, especially within
Assumption 2) There is enough
urban areas [10]. Fundamentally,
road capacity to meet the surge
drivers exhibit different values of
in demand from modal shift due
time (VoT), i.e., willingness to
to the Assumption 1)
trade-off money for ability to travThis assumption concerns the ability
el faster, including crossing
of the road infrastructure to aca junction sooner or drive at
commodate the additional vehicle
higher speeds. VoT itself is driven
trips resulting from the removal of
by broader time use and budrail and public transport. To maintain
get (income) considerations [11].
a similar level of social welfare, i.e.,
Allowing vehicle controllers to
to not make travelers worse off, this
reflect those heterogeneous VoT
would imply a comparable generalin driving style could limit stabiliized cost of travel, including travel
ty of the vehicle platoons, which
duration, monetary costs, or waiting
in turn is key to the postulated
time. Considering the prevalent satutraffic capacity gains [8]. There
ration of road networks across cities,
are emerging ideas that seek to
especially during peak times, this
accommodate this heterogenewould require a substantial increase
ity, e.g., via peer-to-peer trading
in road capacity. To meet this
[12]. Those still require, howevrequirement, it would be necessary
er, suitable technologies and
to combine a set of far-reaching meaprotocols, especially if the benesures that include:
fits are to be realized at the sys■ Ensuring rapid take-up of and
tem level. Alternatively, an exterpenetration of traffic flows by
nally imposed regime of travel
driverless vehicles. This rebehaviors would deprive travelers
quirement rests on extensive
of mobility choices that they
simulation efforts, e.g., [9], provcan currently match to broader life circumstances, thus aling that a high penetration rate
most surely making the users
of driverless vehicles is crucial
worse off.
for achieving higher traffic
■ Broader economic justificathroughput, given the substantion and social acceptance of
tial differences between driving
road expansion projects,
logic in human-controlled and
especially in dense urban
driverless vehicles.
■ Cooperative operation of the
areas. Substantial physical road
vehicles and their controllers.
infrastructure expansion might

This vision can be true, but it
embodies a number of implicit, but
fundamental assumptions. Therefore,
let us spell out these assumptions
and evaluate them in light of current
knowledge, as part of the accepted
best practice to appraise decisions
concerning transport systems.

Assumption 1) Every traveler has
access to a driverless vehicle that
can serve his or her mobility
needs at least as well as
current rail and other public
transport services
This requirement stems from the
need to serve those previously traveling by rail and possibly other public
transport with a similar or better level
of service (generalized cost) in order
to maintain a similar level of social
welfare. To meet those needs, for
example, New York City would need
to serve the current 1.7 billion annual trips made by the subway [6] with
access to driverless vehicles. For
simplicity, assume a homogenous
demand across days of the year and
a vehicle occupancy of 3 persons per
vehicle (seen typically only in high
occupancy lanes). Under those, very
favorable circumstances, the city
would need to cope with about 1.5
million additional vehicle trips per
day, i.e., an increase by a third from
the present 4.5 million [7]. The question remains where the vehicles (and
resources to maintain them) would
come from in order to serve all the
commuters who currently rely on
JUNE 2019

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IEEE TECHNOLOGY AND SOCIETY MAGAZINE

IEEE Technology and Society Magazine - June 2019

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