Source: adapted from Woxenius, J. (2006) “A Time Perspective on Transportation
in Global Production Networks”, Growth and Change, Vol 37, No. 4.
Different Components of Transport Time
Transport time is also an important dimension in the evaluation of
transport costs, particularly since logistics concomitantly involves cost and
time management. The major time related elements are:
Transport time. Concerns the real duration of a transport, which
tend to be easily understood since commonly a proportional function of
distance. Geographical constraints such as weather or technical limitations
such as operational speed have a direct impact on transport time. Transport
time on road is technically limited to legal speed limits. For maritime and
air, the limitation mainly concerns fuel economy and design speed. Although
rail can accommodate a variety of speeds, tight schedules impose limited
variations in operational speeds.
Order time (not shown). Almost all transport requires a form of
advance preparation, mainly to secure a capacity, an itinerary and a
rate. In some cases, the order time is short and a matter of queuing on a
first come first served basis, while in others orders have to be secured
months in advance.
Timing. Involves the usage of a specific departure time, which
depending on the mode can have a level of flexibility. While for air and
rail travel timing is commonly tight due to fixed schedules and access to
intermodal capacity (such as a gate and a takeoff time) commuters and
trucking have more flexibility. If there is congestion either at the origin,
destination or in between, trucking companies may elect to modify their
schedule accordingly (earlier or later delivery).
Punctuality. The ability to keep a specified schedule, which can be
represented as an
average deviation from a scheduled arrival time. The longer the distance,
the more likely are potential disruptions may affect punctuality. Some
movements may have a level of tolerance to disruptions in punctuality while
others, such as heading to a business meeting or flows in a just-in-time
supply chain, have limited tolerance.
Frequency. The number of departures for a specific time range.
The higher the frequency, the better the level of service. However, a high
frequency ties up a larger quantity of vehicles. Distance is also a factor for lower frequency since
transport demand tends to decline accordingly. Combining long distance
travel and frequency is an expensive undertaking for transport providers as
a greater number of vehicles must be assigned to a specific route, as the
case of maritime container shipping indicates.