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The Urban Road Safety Plan
(PSSU): the case study of Brescia
Cagliari, 10-12 maggio 2012
(PSSU): the case study of Brescia
Eng. Margherita CADEI
PhD student in “Places and times of the city and territories”
University of BresciaFaculty of Engineering - DICATA
margherita.cadei@ing.unibs.it
INTRODUCTION
Urban Road Safety Plan (Piano Della Sicurezza Stradale Urbana – PSSU) has been
introduced in Italy in 2001
(Ministry of the Public Works Circular n.3698 “Piani della sicurezza stradale urbana –
Linee guida per la redazione”, Rome, June 8th 2001)
BRESCIA (Middle-sized city; population: about 200.000 people; surface: about 90
km2)
First PSSU elaborated in 2009
PSSU: a planning tool to manage road
INPUT 2012 – Cagliari 10-12 may 2012 Eng. Margherita Cadei – University of Brescia
PSSU: a planning tool to manage road
safety at local level (urban areas) in an
organic and systemic way.
Based on road accident data analysis, it is
able to detect the road accident problems
on the urban road network and to offer
objective criteria to make choices.
Before: decisions about road safety based
on extemporary choices or warnings coming
from the population.
A PSSU’s main document (Piano Direttore) contains:
- aggregate analysis of the road accident data;
- detection of the network “Black spots”;
- definition of quantitative objectives and list of actions/strategies to be implemented;
- quantification of costs/benefits;
- definition of the monitoring process and coordination of the plan.
One of the most important purpose of a PSSU consists in making lists of critic
INPUT 2012 – Cagliari 10-12 may 2012 Eng. Margherita Cadei – University of Brescia
One of the most important purpose of a PSSU consists in making lists of critic
sites where infrastructural interventions are more urgent (“Black spots”).
It’s important to use adequate indicators to express the level of risk of the
network segments.
A PSSU’s main document (Piano Direttore) contains:
- aggregate analysis of the road accident data;
- detection of the network “Black spots”;
- definition of quantitative objectives and list of actions/strategies to be implemented;
- quantification of costs/benefits;
- definition of the monitoring process and coordination of the plan.
One of the most important purpose of a PSSU consists in making lists of critic
INPUT 2012 – Cagliari 10-12 may 2012 Eng. Margherita Cadei – University of Brescia
One of the most important purpose of a PSSU consists in making lists of critic
sites where infrastructural interventions are more urgent (“Black spots”).
It’s important to use adequate indicators to express the level of risk of the
network segments.
A PSSU’s main document (Piano Direttore) contains:
- aggregate analysis of the road accident data;
- detection of the network “Black spots”;
- definition of quantitative objectives and list of actions/strategies to be implemented;
- quantification of costs/benefits;
- definition of the monitoring process and coordination of the plan.
One of the most important purpose of a PSSU consists in making lists of critic
INPUT 2012 – Cagliari 10-12 may 2012 Eng. Margherita Cadei – University of Brescia
One of the most important purpose of a PSSU consists in making lists of critic
sites where infrastructural interventions are more urgent (“Black spots”).
It’s important to use adequate indicators to express the level of risk of the
network segments.
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In Brescia: ROAD ACCIDENT RATE (for each “homogeneous road segment i”):
Instead of calculating the road accident rate for road segments belonging to single
itineraries and instead of comparing the segments’ rate with two threshold values
(CNR,1998) in Brescia each road segment rate is compared with the average
value calculated for the road functional class to which the road segment belongs
(Maternini, 2000).
INPUT 2012 – Cagliari 10-12 may 2012 Eng. Margherita Cadei – University of Brescia
Id Road segment Ti
21 VIA MILANO 2,71
44 VIA CROCIFISSA 2,38
35 VIA ZIMA 2,34
50 P.LE SPEDALI 2,32
13 VIA CHIUSURE 2,30
49 VIA DAL MONTE 2,26
20 VIA MILANO 2,23
40 V.LE PIAVE 1,94
… … …
This indicator is able to express the risk related to
road safety: it puts into relation the number of
accidents, the road segment length and the amount
of traffic.
FAULTY ASPECT: Inaccuracy inherently contained
in the Istat road accident data (Tiboni, 2004)
The exact localization is not always possible;
Uniform distribution of the incomplete data!
SOME CRITICALITIES ABOUT THE ELABORATION OF THE PSSU:
ENDOGENIC FACTORS EXTERNAL FACTORS
- quality of the Istat road accident data:
- imprecise mapping introduces a
systemic error in the road accident
rate calculation;
- late delivery of the Istat data
makes unfeasible the monitoring of
the actions (PSSU life time spans 2
years)
- PSSU is just a “mandatory task”: it
is elaborated but not actually
implemented;
- lack of a strong policy towards the
road safety issues:
- inadequate resources
assignment for the
INPUT 2012 – Cagliari 10-12 may 2012 Eng. Margherita Cadei – University of Brescia
years)
- disaggregate analysis
methodologies based on road
accident scenarios/collisions
diagrams cannot be easily applied
- the Ministry Guidelines are, in some
parts, vague/incomplete:
- cost/benefit analysis;
- the “participated plan process” is
not sufficiently promoted
assignment for the
implementation plans;
- scarce coordination among
the technical departments in
delivering the road safety
projects/plan updating
SOME CONCLUSIONS
There are still some aspects that makes road safety planning/implementation
difficult;
it is hoped a wider application of the good practices available in
literature/resarches in this field;
it is hoped a review/enhancement of the present Ministry guidelines;
a stronger integration between the road safety and the already existing
INPUT 2012 – Cagliari 10-12 may 2012 Eng. Margherita Cadei – University of Brescia
a stronger integration between the road safety and the already existing
urban/mobility planning tools should be promoted.
The Urban Road Safety Plan (PSSU):
Cagliari, 10-12 maggio 2012
:: Thank you for your attention ::
The Urban Road Safety Plan (PSSU):
the case study of Brescia
Eng. Margherita CADEI
PhD student in “Places and times of the city and territories”
University of Brescia
Faculty of Engineering - DICATA
margherita.cadei@ing.unibs.it