
Principles of Modal Shift
A modal shift occurs when one mode (A) has a comparative advantage
in a similar market over another (B). Comparative advantages can take
various forms, such as costs, capacity, time, flexibility or reliability.
Depending on what is being transported, the importance of each of these
factors vary. For some, time is of the essence and a modal shift will
occur only if the new mode offers time improvements, while for others
it is mostly a matter of costs. The outcome is a series of decision
made by firms (for freight) or individuals (for passengers) to shift
to a more convenient mode if comparative advantages are significant
enough. This process often takes place over three phases:
- Inertia. Initially, a strong level of inertia makes the
modal shift a slow and sometimes difficult to perceive process.
Only a few users will experiment with modal shift, often as part
of a publicly subsidized initiative (government providing the initial
funding to develop infrastructures). Inertia implies that the modal
shift is often much less significant than expected, leading to a
situation of underperformance. The reasons behind the inertia are
linked to accumulated investments and assets in the existing mode and
its terminals. Thus, a corporation will be reluctant to relinquish those
assets even if the comparative advantages of the other mode are
significant. Management preferences also play a role as expertise
was developed to manage flows on the previous mode and may be difficult
to adapt to the new mode. The negotiation of new procedures and
contracts are certainly tasks corporations are unwilling to undertake
if the benefits are not readily apparent. The fact that the existing
mode has a proven reliability, even if costly, will also play in
delaying a potential modal shift. Early adopters of a modal shift
are thus likely to be new transport ventures willing to risk testing
an unproven distribution system for the potential rewards of being
the first, enterprises facing already very high transport costs
on the existing mode, or "welfare statists" receiving government
subsidies to do so.
- Shift. The shift phase represents a fast transition from
one mode to the other as the advantages are now acknowledged by
the industry. The new transport mode evolves from a situation of
underperformance to one of over performance. As inertia involved
a modal shift taking place at a rate lower than expected, during
the shift the transition rate is faster than expected. This can
take users and authorities by surprise with a rush to cope with
the transition with additional infrastructure investments. The significant
drop in comparative advantages as the new mode gets increasingly
congested and/or as the previous mode loses traffic (closing of
some routes, rationalization, price cutting, etc.), triggers the
end of this phase.
- Maturity. At this point the potential is reached and
a new equilibrium in modal share is reached. Their respective comparative
advantages are of lesser variance.
Thus a modal shift takes place in a context where from a macro perspective
there are changes in the transport supply and from a micro perspective
the decisions (behavior) of individuals (passengers) and firms (mostly
for freight) is changing.