  The Physical Internet (PI) puts high emphasis on enabling logistics to
reliably perform at the speed mandated by and promised to customers, and to do
so efficiently and sustainably. To do so, goods to be moved are encapsulated in
modular containers and these are flowed from hub to hub in relay mode. At each
hub, PI enables fast and efficient dynamic consolidation of sets of containers
to be shipped together to next hubs. Each consolidated set is assigned to an
appropriate vehicle so to enact the targeted transport. In this paper, we
address the case where transportation service providers are available to
provide vehicles and trailers of distinct dimensions on demand according to
openly agreed and/or contracted terms. We describe the essence of such terms,
notably relative to expected frequency distribution of transport requests, and
expectations about time between request and arrival at hub. In such a context,
we introduce rigorous generic protocols that can be applied at each hub so as
to dynamically generate consolidation sets of modular containers and requests
for on-demand transportation services, in an efficient, resilient, and
sustainable way ensuring reliable pickup and delivery within the promised time
windows. We demonstrate the performance of such protocols using a
simulation-based experiment for a national intercity express parcel logistic
network. We finally provide conclusive remarks and promising avenues for field
implementation and further research.
