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David Vetturi, Giulio Maternini , Matteo Lancini, Ileana Bodini

University of Brescia DIMI - Mechanical and Industrial Engineering

DICATA - Civil Engineering, Architecture, Land and Environment

PURPOSES

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� Evaluation of the effects of the traffic calming

measures on the accelerations (comfort) perceived

by passengers of the road public transport

� A low cost device to easily measure and supervise

the level of vibration on the road public transport

network

CONTEXT

� Improve road safety by traffic calming measures (roundabouts, speed bumps, different pavements))The United Nations General Assembly has set the goal for the decade: "to stabilize and then reduce the forecast level of road traffic fatalities around the world" by 2020.

� Control the exposure of workers and passengers to the

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� Control the exposure of workers and passengers to the vibration on public transport vehicles (urban and local)Implementation of the Directive 2002/44/EC of the European Parliament and of the Council on the

minimum health and safety requirements regarding the exposure of workers to the risk arising from

physical agents (vibration) – DLGS 19.08.2005 N. 187

� Control the quality of transportationImplementation of the European standard EN 13816 – UNI EN 13186, the purpose of which is “to

promote a quality approach to public transport operations and focus interest on customers’ needs and

expectations”. Ride comfort is one of the quality criteria (6.3)

INVOLVED BODIES

Companies of the public

Mechanical

engineers

design comfortable vehicles for the public transport

control the good level of comfort for the passengers and the operators of the public

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the public transport

Owner body

concerned

Civil engineers

passengers and the operators of the public transport

supervise the maintenance works on the road network

design safer roads using correctly the traffic calming measures

OBJECT OF THE MEASUREMENT

� Level of comfort:

acceleration in three principal orthogonal directions,

conveniently weighted in frequency and reduced to a

RMS value

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RMS value

� Location:

absolute coordinates (WGS84) to obtain vehicle

position along the route

MEASURE & DATA ANALYSIS

� MEASURE:

� GPS position and speed of the vehicle (1 Hz)

� X, Y, Z acceleration on the floor of the vehicle (10 kHz)

� DATA ANALISYS

� Acceleration weighting (UNI-ENV 12299)

� Definition of a synthetic

comfort index :NVM & NVD

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� TIME RE-SCALING

� Synthetic data are store with a frequency of 10 Hz

INSTRUMENTATION

Compact RIO Unit

NI cRIO-9022

K-Beam® Accelerometer

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K-Beam® Accelerometer

8393B10

GPS device

Database

DAQ - NI 9215

INSTRUMENTATION

Positioning of the DAQ system (CompactRIO)

and energy supply (battery)

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Accelerometer fixed

at the floor

GEOGRAPHICAL DATABASE

Geographic

Information

System

Allows for analysis

based on the

AccessMAPInfo

Acquisition LOG

Synthetic data of a

single acquisition on a

Relational Database

Allows for a structured data

storage in order to aggregate

and disaggregate sample as

needed. Possible parameters

VI LabView

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based on the

geographical

distribution of data

Very large

number of data

recorded in

synthetic form

single acquisition on a

single route

(1h ~200kB)

needed. Possible parameters

could be:

-brand and model of bus

-time of service

-route of service

-driver

Geographical

database to

perform statistical

analysis

: L

ine

a 1

0

BRESCIA

BOVEZZO

CONCESIO

Tra

ck:

Lin

ea

10

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DETTAILEDANALYSIS

PRESENTED

FLERO

PONCARALE

CASE OF STUDY

•20 hours of data acquisition

•Different traffic conditions

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Model:

IRISBUS (Iveco) 491.12 CityClass

Dimension:

12 m

2.5 m

•Different whether condition

ZONE

A

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Villaggio

Sereno

Traversa Diciottesima

ZONE

B

ZONE A

BUS STOPBUS STOP

ROUNDABOUTROUNDABOUT

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STRAIGHT ROADSTRAIGHT ROAD

Lateral acceleration “Y”

Repeatability of data acquisition

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Vertical Acceleration “Z”

STRAIGHT ROAD: via Flero

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Acquisizioni NMV (medio)

10-nov 4.3

14-nov 4.1

16-nov 4.3

Acquisizioni NVD (medio)

10-nov 5

14-nov 4.2

16-nov 5

BUS STOP: via Corsica

1 2

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Acquisizioni NMV₁ NMV₂ NMV (medio)

10-nov 9.6 6.2 3.5

14-nov 8.8 4.2 3

16-nov 8.4 6.7 3.7

Acquisizioni NVD₁ NVD₂ NVD (medio)

10-nov 19.9 13 6.9

14-nov 18.7 9 6.1

16-nov 17.4 14 5.4

1

2

ZOOMING

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Three different situation:

• Approach to the stopping point

• Noise when speed is zero

• Discomfort in the bus restarting

1 2 3

ROUNDABOUT: via Corsica - via Flero

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Acquisizioni NMV₁ NMV₂ NMV₃ NMV (medio)

10-nov 5.4 11.5 11.5 6.1

14-nov 6 11.4 11 5.6

16-nov 6.4 11.6 11.6 6.2

Acquisizioni NVD₁ NVD₂ NVD₃ NVD (medio)

10-nov 8.7 22.2 21.9 11.2

14-nov 12.4 21.7 20.2 10.3

16-nov 10.5 22.5 21.2 11.5

1

2 3

ZOOMING

Three different situation:

• Approach to the roundabout

• Max value of discomfort inside roundabout

• Roundabout exit

� Roundabout diameter: 20 m

ACQUISITION

NVD

IN CENTER OUT

1 8.4 21.3 12.1

2 9.5 22.4 14.1

Via Brazne

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ACQUISITIONNMV

IN CENTER OUT

1 4.2 10.0 5.8

2 4.4 12.1 6.7

3 5.1 12.0 7.1

3 10.2 22.1 14.5

Mean value:

NVD 11.0 ÷ 12.0

NMV 5.0 ÷ 6.0

Via Campane

ACQUISITION

NVD

IN CENTER OUT

1 10.3 20.6 9.5

2 8.0 21.3 12.7

� Roundabout diameter: 20 m

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ACQUISITIONNMV

IN CENTER OUT

1 5.6 11.5 5.0

2 3.8 11.3 6.5

3 5.2 11.1 4.4

2 8.0 21.3 12.7

3 9.7 19.5 9.0

Mean Value:

NVD 11.0 ÷ 13.0

NMV 6.0 ÷ 7.0

ACQUISITION

NVD

IN CENTER OUT

1 15.8 26.1 14.0

2 15.7 24.0 12.2

3 17.0 21.0 10.3

Via Conicchio

� Roundabout diameter: 30 m

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ACQUISITIONNMV

IN CENTER OUT

1 7.5 13.6 7.6

2 10.2 12.8 7.0

3 8.1 10.8 5.7

Mean Value:

NVD 12.0 ÷ 13.0

NMV 6.0 ÷ 7.0

ZONE B

RAISED PEDESTRIAN CROSSING RAISED PEDESTRIAN CROSSING

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RAISED PEDESTRIAN CROSSING

Speed [km/h]

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Space [m]

RAISED PEDESTRIAN CROSSING

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1 2

RAISED PEDESTRIAN CROSSING

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Acquisizioni NVD₁ NVD₂ NVD (medio)

10-nov 15.4 15.6 8.5

14-nov 4.1 6.7 5.2

16-nov 18 13 8.9

Acquisizioni NMV₁ NMV₂ NMV (medio)

10-nov 7.1 10.9 5.3

14-nov 2.4 9.2 3.7

16-nov 8.3 10 5.3

1 2

C₁ C₂ C₃ C(MEDIO) C₁ C₂ C₃ C(MEDIO)

NMV NVD

Roundabout

indexcomfortreference

indexcomfortmeasuredc

=

RELATIVE INDEX

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1.4 2.7 2.7 1.4 2.2 4.7 4.5 2.3

C₁ C₂ C(MEDIO)

1.4 2.4 1.1

C₁ C₂ C(MEDIO)

2.7 2.5 1.6

NMV NVD

C₁ C₂

2.1 1.4

C₁ C₂

4.0 2.6

NMV NVD

Raised Pedestrian Crossing

Bus Stop

CONCLUSION

• A methodology for comfort evaluation has been proposed

• A validation of the index proposed

• Investigate the infrastructural elements effects on comfort

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NEXT

Increase the database

Define and validate a “COMFORT SCALE” using other objective and subjective information (video recording, passenger interview, …)