Within this scope, this paper presents an innovative methodology
for the reduction of the total operation cost (including partial
costs for vehicles maintenance, labor and fuel) involved in the
waste collection and transportation. Its innovative feature lies
mainly in combining collection scheduling based on historical data
of the individual container fill-up rates with vehicle route optimization
in GIS environment. The proposed collection scheduling is
more realistic than the usual assumption of a single average fillup
rate value applied to all the system containers and allows for
more adequate and ahead collection planning. As far as GIS is concerned,
it significantly simplifies the vehicle routing optimization
process, representing and visualizing efficiently and conveniently
the obtained results. In addition, for calculating the fuel consumption
and intrinsic amount of released pollutant emissions originated
from vehicles operation during waste collection and
transportation, the main influencing factors and their variation
are taken into consideration, rather than using their average values.
Such factors are the different vehicle speeds corresponding
to different types of roads, and the changing loading weight as a
consequence of picking-up waste at each visited container. To
the best of the present authors’ knowledge, the methodology proposed
herein, combining route optimization in GIS environment
with prior collection scheduling, has not previously been reported.
The established methodology was applied to study the system of
the glass-waste collection and transportation of the waste collection
of Amarsul S.A., in Barreiro. As direct effects of the above combined
optimization, expected fuel consumption decrease and,
consequently, a decrease of the pollutant emissions (CO, CO2,
NOx and PM) of the heavy-duty vehicles in the fleet assigned for
the task are analyzed.