Ramp Metering

1
Ramp Metering

• New experiences
• in Nordrhein Westfalen
• By
• René Usath,
• Landesbetrieb Straßenbau
• Nordrhein-Westfalen,
• Centrico

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Ramp Metering New experiences in NRW
Traffic Management and Control
A 40 The arterial road of the Ruhrgebiet
Experiences with the new ramp metering systems in
general
The development of congestions and incidents
The new design of signing (Centrico contrast
shield Centrico Kontrastscheibe)
Coordination of 37 ramp metering systems on A 40
A ramp metering system in parallel and tangential
lane in the access point  Bochum-Zentrum 
Provisional ramp metering with a roadworks
traffic light
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Ramp Metering New experiences in Nordrhein
Westfalen
Ramp Metering

• The motorway A 40 is the major arterial road in
  the conurbation Ruhrgebiet.

Introduction A 40
General Experiences
Incidents and Congestions
New signing
Coordination
Bochum- Zentrum
Provisional Ramp Metering
4
Ramp Metering New experiences in Nordrhein
Westfalen
Ramp Metering
Introduction A 40
General Experiences
Incidents and Congestions
New signing
Coordination
Bochum- Zentrum
Provisional Ramp Metering
5
Ramp Metering New experiences in Nordrhein
Westfalen
Ramp Metering

• The motorway A 40 is the major arterial road in
  the conurbation Ruhrgebiet.

It is the connection between large settlement
areas in the conurbation as well as an important
east-west axis for long distance transportation.
The average daily traffic amounts to 132,000
vehicles. In 1998, a stretch control system got
started as a first step to improve traffic flow.
This was followed by five ramp metering systems
as a pilot in Germany in 1999.
Introduction A 40
General Experiences
Incidents and Congestions
New signing
Coordination
Bochum- Zentrum
Provisional Ramp Metering
6
Ramp Metering New experiences in Nordrhein
Westfalen
Ramp Metering
Introduction A 40
General Experiences
Incidents and Congestions
New signing
Coordination
Bochum- Zentrum
Provisional Ramp Metering
7
Ramp Metering New experiences in Nordrhein
Westfalen
Ramp Metering

• The motorway A 40 is the major arterial road in
  the conurbation Ruhrgebiet.

It is the connection between large settlement
areas in the conurbation as well as an important
east-west axis for long distance transportation.
The average daily traffic amounts to 132,000
vehicles. In 1998, a stretch control system got
started as a first step to improve traffic flow.
This was followed by five ramp metering systems
as a pilot in Germany in 1999.
Introduction A 40
General Experiences
Incidents and Congestions
The positive effects of these pilots resulted in
the installation of additional systems.
Consequently 13 further systems have been
operational since May 2003.
New signing
Coordination
Special aspects in the presentation are
Bochum- Zentrum

• the development of incidents and congestion

Provisional Ramp Metering

• the new design of signing

• the coordination of 37 ramp metering systems on
  A 40

• a ramp metering system in parallel and
  tangential lane in intersection Bochum-Zentrum

• provisional ramp metering

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Experiences with the new ramp metering systems in
general
Ramp Metering

• Almost all access points on A 40 in Bochum are
  ramp metered, two access points in Essen

Introductíon A 40

• Some junctions with a high rate of flow (1.200
  1.500 vehicles in peak hours), short ramps and/or
  difficult conditions in the secondary network
  (theoretical maximum capacity of ramp metering is
  720 vehicles per hour 2 seconds red, 1
  red-yellow, 1 green, 1 yellow 5 seconds per
  cycle, resulting in 12 vehicles per minute)

General Experiences
Incidents and Congestions
New signing

• Most problems occurred in Essen, a new situation
  for the drivers and the local politicians, local
  newspapers demanded switching off of ramp
  metering

Coordination

• In the first days there were some malfunctions

Bochum- Zentrum

• loops did not work together

• Softwareproblems, such as programs working too
  inert

Provisional Ramp metering

• behaviour of the drivers could not be simulated

• With fine-parametring every system has been
  optimized and almost all problems could be
  solved, only few features are still unreliable,
  for example sliding switching off is still
  inactive

• The consulting engineers office entrusted to
  build further systems at other junctions as soon
  as possible because of very good experiences

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The Development of congestions and incidents
Ramp Metering

• The pilot systems were screened by a report auf
  an enginneers office, with very positive
  results

Introduction A 40

• 40 less accidents

General Experiences

• 50 less congestions

Incidents and congestions

• average speed in peak hours raises by 10 km/h

New signing

• These positive effects in the area with
  additional ramp metering could be confirmed in
  the meantime, the number and duration of
  congestions and the average speed are on the same
  level like 1999.

Coordination

• But there is an enormous decrease in the number
  off accidents in 54 from 1998 (inauguration of
  stretch control system) till 2002. The number of
  type-6-accidents (in congestions) decreases in 52
  . This is remarkable, because in this section
  surface is quite old with low skid resistance.

Bochum- Zentrum
Provisional Ramp Metering
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The Development of congestions and incidents
Ramp Metering
Introduction A 40
General Experiences
Incidents and congestions
New signing
Coordination
Bochum- Zentrum
Provisional Ramp Metering
11
The Development of congestions and incidents
Ramp Metering

• The pilot systems were screened by a report auf
  an enginneers office, with very positive
  results

Introduction A 40

• 40 less accidents

General Experiences

• 50 less congestions

Incidents and congestions

• average speed in peak hours raises by 10 km/h

New signing

• These positive effects in the area with
  additional ramp metering could be confirmed in
  the meantime, the number and duration of
  congestions and the average speed are on the same
  level like 1999.

Coordination

• But there is an enormous decrease in the number
  off accidents in 54 from 1998 (inauguration of
  stretch control system) till 2002. The number of
  type-6-accidents (in congestions) decreases in 52
  . This is remarkable, because in this section
  surface is quite old with low skid resistance.

Bochum- Zentrum
Provisional Ramp Metering

• In the field of the new signalisations the
  average speed in peak hours is nearly doubled, it
  is obvious that the number of congestions
  decreases in a similiar magnitude.

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The Development of congestions and incidents
Ramp Metering
Introduction A 40
General Experiences
Incidents and congestions
New signing
Coordination
Bochum- Zentrum
Provisional Ramp Metering
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The new design of the signing (Centrico contrast
shield Centrico Kontrastscheibe)
Ramp Metering
Introduction A 40

• Yellow shield around the signal to strengthen
  contrast between signal and surroundings

General Experiences
Incidents and Congestions

• Additional signing in form of a text 1 Fahrzeug
  bei Grün One car per green

New signing
Coordination
Bochum- zentrum
Provisional Ramp Metering
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The new design of the signing (Centrico contrast
shield Centrico Kontrastscheibe)
Ramp Metering
Introduction A 40
General Experiences
Incidents and Congestions
New signing
Coordination
Bochum- zentrum
Provisional Ramp Metering
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Coordination of 37 ramp metering systems on A 40
Ramp Metering
Introduction A 40

• Existing stretch control system on A 40 between
  Mülheim and Bochum

General Experiences
Incidents and Congestions
New Signing
Coordination
Bochum- Zentrum
Provisional Ramp metering
16
Coordination of 37 ramp metering systems on A 40
Ramp Metering
Introduction A 40
General Experiences
Incidents and Congestions
New Signing
Coordination
Bochum- Zentrum
Provisional Ramp metering
17
Coordination of 37 ramp metering systems on A 40
Ramp Metering
Introduction A 40

• Existing stretch control system on A 40 between
  Mülheim and Bochum

General Experiences

• 13 systems already working (five pilots plus
  eight since May 5th, 2003)

Incidents and Congestions
New Signing

• 24 further systems are planned and are going to
  be installed in the next two years

Coordination

• Existing infrastructure (radar detectors at the
  overhead sign structure

Bochum- Zentrum
Provisional Ramp metering
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Coordination of 37 ramp metering systems on A 40
Ramp Metering
Introduction A 40
General Experiences
Incidents and Congestions
New Signing
Coordination
Bochum- Zentrum
Provisional Ramp metering
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Coordination of 37 ramp metering systems on A 40
Ramp Metering
Introduction A 40

• Existing stretch control system on A 40 between
  Mülheim and Bochum

General Experiences

• 13 systems already working (five pilots plus
  eight since May 5th, 2003)

Incidents and Congestions
New Signing

• 24 further systems are planned and are going to
  be installed in the next two years

Coordination

• Existing infrastructure (radar detectors at the
  overhead sign structure,

Bochum- Zentrum
sub-centrals, data transmission) will be used
good value
Provisional Ramp metering

• According to the extraordinary importance for the
  whole region and due to the character of an
  innercity motorway (partly deep clefts, very high
  density of building nearby, several tunnels which
  makes complete extension on six lanes too
  expensive), all techniques of traffic engineering
  are applied to improve traffic flow

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A ramp metering system in parallel and tangential
lane in the access point Bochum-Zentrum
Ramp Metering

• Situation

Introduction A 40
General Experiences
Incidents and Congestions
New signing
Coordination
Bochum- Zentrum
Provisional Ramp Metering

• Double access point with parallel lanes in both
  directions

• Four accesses and very interesting five exits

• Reason for this kind of intersection to minimize
  left-turns in the secondary network, one
  departure into an trading and industrial area

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A ramp metering system in parallel and tangential
lane in the access point Bochum-Zentrum
Ramp Metering

• Situation

Introduction A 40

• Double access point with parallel lanes in both
  directions

General Experiences

• Four accesses and very interesting five exits

Incidents and Congestions

• Reason for this kind of intersection to minimize
  left-turns in the secondary network, one
  departure into an trading and industrial area

New signing

• Ramp Metering

Coordination

• Signalization of parallel lane and ramp traffic
  responsive either ramp or parallel lane gets
  green it is thus possible, to have several
  cycles at one signal while the other signal is
  red

Bochum- Zentrum

• Loops queue detector, early-check-in detector,
  check-in detector, check-out detector (in ramp
  and parallel lane)

Provisional Ramp Metering

• Signing over-head sign (prism turns) in the
  parallel lanes (Zuflussregelung ramp
  metering) with two yellow flash lightnings, in
  the secondary network 10 signings (five per
  direction)

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A ramp metering system in parallel and tangential
lane in the access point Bochum-Zentrum
Ramp Metering
Introduction A 40
General Experiences
Incidents and Congestions
New signing
Coordination
Bochum- Zentrum
Provisional Ramp Metering
23
A ramp metering system in parallel and tangential
lane in the access point Bochum-Zentrum
Ramp Metering

• Situation

Introduction A 40

• Double access point with parallel lanes in both
  directions

General Experiences

• Four accesses and very interesting five
  departures

Incidents and Congestions

• Reason for this kind of intersection to minimize
  left-turns in the secondary network, one
  departure into an trading and industrial area

New signing

• Ramp Metering

Coordination

• Signalization of parallel lane and ramp traffic
  responsive either ramp or parallel lane gets
  green it is thus possible, to have several
  cycles at one cycle while the other signal is red

Bochum- Zentrum

• Loops queue detector, check-in detector,
  early-check-in detector, check-out detector (in
  ramp and parallel lane)

Provisional Ramp Metering

• Signing over-head sign (prism turns) in the
  parallel lanes (Zuflussregelung ramp
  metering) with two yellow flash lightnings, in
  the secondary network 10 signings (five per
  direction)

• Anti-dazzle barrier length 24 metres, between
  main and parallel lane

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A ramp metering system in parallel and tangential
lane in the access point Bochum-Zentrum
Ramp Metering
Introduction A 40
General Experiences
Incidents and Congestions
New signing
Coordination
Bochum- Zentrum
Provisional Ramp Metering
25
A ramp metering system in parallel and tangential
lane in the access point Bochum-Zentrum
Ramp Metering

• Situation

Introduction A 40

• Double access point with parallel lanes in both
  directions

General Experiences

• Four accesses and very interesting five
  departures

Incidents and Congestions

• Reason for this kind of intersection to minimize
  left-turns in the secondary network, one
  departure into an trading and industrial area

New signing

• Ramp Metering

Coordination

• Signalization of parallel lane and ramp traffic
  responsive either ramp or parallel lane gets
  green it is thus possible, to have several
  cycles at one cycle while the other signal is red

Bochum- Zentrum

• Loops queue detector, check-in detector,
  early-check-in detector, check-out detector (in
  ramp and parallel lane)

Provisional Ramp Metering

• Signing over-head sign (prism turns) in the
  parallel lanes (Zuflussregelung ramp
  metering) with two yellow flash lightnings, in
  the secondary network 10 signings (five per
  direction)

• Anti-dazzle barrier length 24 metres, between
  main and parallel lane

• Questionable departing vehicles are metred, but
  in practice no problems noticed because of small
  number of departing vehicles, solution could be
  closing of this departure

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A ramp metering system in parallel and tangential
lane in the access point Bochum-Zentrum
Ramp Metering
Introduction A 40
General Experiences
Incidents and Congestions
New signing
Coordination
Bochum- Zentrum
Provisional Ramp Metering
27
Provisional ramp metering with a roadwork traffic
light
Ramp Metering

• Situation acces point Schwerte on A 1

Introduction A 40

• 80.000 vpd, restricted lanes and shortened ramp
  (50 meters)

General Experiences

• Roadworks for more than two years because of an
  extension into six lanes

• 250 congestions per year, average duration 2 h 30
  mins

Incidents and Congestions

• High accident rate

New signing
Coordination
Bochum- Zentrum
Provisional ramp metering
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Provisional ramp metering with a roadwork traffic
light
Ramp Metering
Introduction A 40
General Experiences
Incidents and Congestions
New signing
Coordination
Bochum- Zentrum
Provisional ramp metering
29
Provisional ramp metering with a roadwork traffic
light
Ramp Metering

• Situation acces point Schwerte on A 1

Introduction A 40

• 80.000 vpd, restricted lanes and shortened ramp
  (50 meters)

General Experiences

• Roadworks for more than two years because of an
  extension into six lanes

• 250 congestions per year, average duration 2 h 30
  mins

Incidents and Congestions

• High accident rate

New signing

• Ramp metering

Coordination

• As a first step ramp closing depending on state
  of traffic and later closing during peak hours
  from 600 to 900 a.m.

Bochum- Zentrum

• Followed by pretimed-liked metering with
  self-sufficient road work traffic lights and some
  infra-red detectors ? low acceptance

Provisional ramp metering

• At last complete traffic-responsive metering with
  check-in and check-out detector, state of
  occupancy and congestion main lane detectors
  according to the state of occupancy of the main
  lane ramp is metered in rates between 2 and 11
  seconds ? high acceptance

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Provisional ramp metering with a roadwork traffic
light
Ramp Metering
Introduction A 40
General Experiences
Incidents and Congestions
New signing
Coordination
Bochum- Zentrum
Provisional ramp metering
31
Provisional ramp metering with a roadwork traffic
light
Ramp Metering

• Situation acces point Schwerte on A 1

Introduction A 40

• 80.000 vpd, restricted lanes and shortened ramp
  (50 meters)

General Experiences

• Roadworks for more than two years because of an
  extension into six lanes

• 250 congestions per year, average duration 2 h 30
  mins

Incidents and Congestions

• High accident rate

New signing

• Ramp Metering

Coordination

• As a first step ramp closing depending on state
  of traffic and later closing during peak hours
  from 600 to 900 a.m.

Bochum- Zentrum

• Followed by pretimed-liked metering with
  self-sufficient road work traffic lights and some
  infra-red detectors ? low acceptance

Provisional ramp metering

• At last complete traffic-responsive metering with
  check-in and check-out detector, state of
  occupancy and congestion main lane detectors
  according to the state of occupancy of the main
  lane ramp is metered in rates between 2 and 11
  seconds ? high acceptance

• Some problems had to be solved, functional
  disorders occurred

• Incorrect positioning of the detectors

• Relaxing of red time too inert

• Congestion detection in the main lanes absolutely
  necessary

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