public transportation with logistics services

two-tired model for a shared passengers &
goods city logistics system. In the first system tier,
goods are collected at a facility called the City
Distribution Center (CDC). From CDC, goods are
then loaded on buses, through the connection with
the bus line. By mixing the two flows, passengers
have priority. Goods, packed in roll containers, are
loaded on the spare capacity of the bus. The
suggested shared transportation model has to ensure
the quality of service to passengers using public
transport. In the second system tier, goods are
unloaded at identified bus stops where they are
transhipped to capillary logistics system using
tricycles that deliver customers through near–zero
emissions city freighters. This approach is much
more flexible. It offers the advantage to adjust at any
time the number of tricycles available at bus stops.
Furthermore, delivery vehicles are synchronized
with buses and ensure the transhipment operation,
and avoid the installation of storage facilities at bus
stops.
2. Suggest a model to dimension the number of
tricycles allowing the satisfaction of the daily
customer demand. We propose a heuristic method to
solve the optimization problem formulated as a
special case of two-echelon vehicle routing problem
with transhipment.