Road network performance improvement including traffic safety study

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Opus International Consultants Ltd. Central
Laboratory, Gracefield, New Zealand
Transportation Group Consultancy Service

• Contact Detail
• Dr Haran Arampamoorthy, B.Sc. Eng. (Civil), PhD,
  ME, CPEng, IntPE(NZ), RPEQ
• Senior Research Engineer (Transportation
  Pavement Engineering)
• Address PO Box 30 845, Lower Hutt, New Zealand

Ph No. 0064 4 5870651 Fax No. 0064 4
5870604 Mob [phone]
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Transportation Group
The transportation group in Opus Gracefield, New
Zealand can provide consultant service on the
following

• Highway Safety Deficiency

• Road Infrastructure Safety Assessment

• Accident Investigation

• Road Safety Audit for Projects
• Highway capacity Deficiency
• Integrated Asset Management

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Offering expert advice on road safety and capacity

• Client can provide the necessary data

• Or our staff can collect the data

• Format of the Desktop analysis output is easily
  understandable

• Advice on finding solutions

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Spatial accident data analysis

• First stage of the accident analysis
• Identify appropriate accident reduction plan by
  identifying the hazardous locations, using
  statistical spatial data analysis techniques,
  which is designed for traffic accident data.
• The hazardous locations and the accident
  reduction plans are
• black spots site action plan
• black route route action plan
• black area area action plan

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Spatial analysis approach

• Quadratic analysis
• Nearest-neighbour analysis (e.g.)

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Highway Safety Study (desk top analysis)

• Highway safety deficiency
• Curve advisory speed signs
• Passing lane assessment
• Input Data
• High speed Road Geometry Data
• SCRIM Data (Friction measurements)
• CAS Data

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Outcome from Highway Safety Study (Desk-top
assessment)

• Identifying Passing Sight Distance deficiency
  locations
• Identifying Stopping Sight Distance deficiency
  locations
• Identifying Friction deficiency locations
• Identifying Curvature deficiency locations
• Identifying potential locations for accidents
  caused by Environment and Local Speed
• Identifying potential locations for accidents
  caused by Cross-fall and Curvature
• Identifying high accident locations.

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• Few examples from Strategy Study outputs
• Lack of passing opportunity results in driver
  frustration and leads to undertake unsafe passing
  manoeuvres.
• Passing difficulties indicated between the RP 2.8
  to 4.4 is mostly below 200 m. (Potential area for
  overtaking accidents).

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• Required Stopping Sight Distance for 100 km/h
  road is around 200 m.
• Identify SSD deficiency locations

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• Friction demand and supply
• Deficiency
• Required friction gt Available friction
• Spikes

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• Problem caused by existing Radius lt Minimum
  Radius
• Remedies
• Increasing superelevation through shape
  correction
• Increasing superelevation (lt10) needs
  Realignment

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• Problem caused by speed
• Deficiency locations
• difference between local speed and speed
  environment gt 15km/h

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• Shows curvature and crossfall
• Identifies adverse camber or excess warp
• Adverse camber (cross fall and curvature in
  different direction)
• Superelevation is effectively negative relative
  to the curve

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Put it All Together With

• Accidents
• Truck Ride
• Swept Path

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Outcome from Curve Advisory Speed Signs Desk-top
assessment

• Helpful to identify the locations where speed
  sign requirement
• Sign may required
• Existing sign may modified or removed

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Curve Advisory Speed Signs Desk-top assessment
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RISA

• Road Infrastructure Safety Assessment
• Background
• Safety Audits of Existing Roads
• Less subjective
• Accident reduction relationships
• On going monitoring

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Road Safety Audit for Projects

• Our staff offer the traditional four stage Road
  Safety Audits Advice.
• Feasibility
• Preliminary
• Detailed design
• Post construction

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Detailed design Stage

• Design data used for desk top study to identify
  deficiency locations
• The out puts are helpful for Auditor to comment
  on
• Passing sight distance deficiency and driver
  frustration
• Stopping sight distance and driver alertness
• Environmental speed and local speed variations
• Friction demand and driver alertness

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Accident Investigation

• Checking site has an atypically high accident
  rate for accident reduction treatment
• Two examples from River road (SH 2)
• (1) Intersections
• (2) Mid-blocks
• Accident rate compared with other similar roads

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Useful to compare the mid Block accident rate
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Useful to identify whether the accidents are
significantly high at those intersections
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Useful to identify the accidents are
significantly related to the locations or random
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Traffic Assessment

• Assess current situation
• Identify key constraints
• Peak Periods
• Growth
• Capacity
• Future Performance
• Identify possible future strategies
• Example of River road (SH 2)

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Integrated Asset Management
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Asset Management

• Transportation Networks are lifelines for the
  Community
• Reliability of these Networks must be improved
• We must put in place Best Practice in risk
  management
• Integrate into NMM actions Asset Management

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Spatial Approach for Networks

• Use of GIS
• to characterise networks
• map networks
• visual presentation of spatial risks
• analysis of risk
• assessment of risk treatment
• prioritisation and justification

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Prioritisation of Road Network

• Route class
• Traffic volumes
• Importance (alternative routes ?)
• Emergency services route
• Public transport routes
• Commercial routes
• Overall risk for road link

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Thank you

• If you need further information on each of the
  six services then please contact us
• Contact details are given in the first slide
• Our experts are willing to help and reduce social
  cost