Environmental Engineering Reference
In-Depth Information
Table 6 Distance covered in the Bordeaux urban area by urban management flows (adapted
from Ségalou et al.
2004
)
Activity
Method of computation
Km/inhab. each
year (% HV
10
)
Public works, demolition
and building sites
500 trucks per week for 100,000 inhabitants 130
heavy vehicles per 1,000 m
2
, numerous light
commercial vehicles
12.1 (81)
Network management
a
and public services
Annual mileage of specific vehicles
17.9 (36)
Household refuse and
industrial waste
collection
Annual mileage of garbage trucks
23.1 (48)
House and enterprise
moving (removals)
10 % of households, stores and firms move each
year.
3.9 (22)
Public postal services
Annual mileage of specific vehicles in the urban
area
8.6 (40)
a
(cleansing, water, gas, electricity and telecommunication)
heavy vehicles. However, the percentage of semi-articulated vehicles and that of
simple trucks is not described here.
7 From Road Occupancy to Environmental Impacts
The model proposed allows estimating road occupancy rates and then the main
macroscopic road occupancy issues concerning urban goods movements. How-
ever, the environmental impacts are also a priority for many stakeholders. For this
reason, an environmental module was added (Ségalou et al.
2004
; Albergel et al.
2005
). It is developed from the fact that the impacts of urban transport on the
environment can be observed at two levels. On the local scale we find the best-
known impacts, i.e. air, ground and water pollution, as well as noise. Congestion is
not considered here since it was included in the basic version of the model (road
occupancy issues obtained from the three modules presented above). On the global
scale, we find two major impacts: energy consumption and greenhouse gas
emissions.
The definition of UGM adopted above takes into account the overall goods
movements carried out in an urban zone. Therefore the traffic generated by the
three types of flows constitutes the total UGM needs to be compared with the two
other types of flow: the freight through traffic (FTT) and the other motorized
private and professional car trips. This typology has the advantage of being built
on the basis of comprehensive data that is also generally statistically available.
Two main models are applied successively, as in the following diagram:
10
HV : Heavy vehicles.
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