The Regional Rollout of Variable Message Signs

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The Regional Rollout ofVariable Message Signs
Murray Russell NZ Transport Agency, and Neil
Garnett Opus International Consultants
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OVERVIEW

• In 2004 the Transit ITS team produced a strategy
  that focused on how technology could play a
  leading role in improving levels of service to
  all state highways.
• Variable Message Signs (VMS) located in strategic
  and key decision making locations throughout New
  Zealand were identified as a top priority.

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WHAT ARE VMS?
INSERT IMAGE HERE
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WHAT ARE NZTA REGIONAL VMS?

• VMS installed at key strategic locations
  throughout NZ
• Fit for purpose based on local environment and
  location
• Communications through Broadband or cellular
• VMS Monitored Controlled by NZTAs in-house
  software application
• Remote changing of messages via web interface
  from any internet linked PC

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Motorway and Regional VMS - Comparison

• Motorway
• Arterial motorway
• High traffic volume
• Multiple lanes
• Character height 400 / 450mm
• Supported on overhead gantry
• Sited in highly populated areas

• Regional
• Regional routes
• Low - moderate traffic volume
• Frequently single lane
• Characters 160 / 200 / 300mm
• Roadside supports
• Frequently remote locations

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Application of Regional VMS

• Incident Management
• Road closures
• Restrictions
• Diversions

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Application of Regional VMS

• Road condition and availability information
• Unusual/hazardous road conditions e.g.
  water/ice/snow
• Unusual/potentially hazardous driving conditions
• Closures/restrictions/diversions
• Special events e.g. running/cycle races
• Travel time information when significant delay

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Software

• NZTA developed in-house software - MACA.
• Reasons not to re-use or buy existing product
  included
• Disparate legacy systems
• Systems were proprietary to vendors
• NZTA had no control over ongoing development
• KISS principle start small and stay focussed on
  own requirements

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Software
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Software

• The VMS MACA Application is a JEE application
  deployed inside the Transit IS environment.
• It supports various types and levels of users
  through a browser-based interface.
• Whenever the application needs to communicate
  with a sign, it sends a request to the VMS
  Gateway Application, which performs the physical
  communication.

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Software Architecture
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Communication Systems

• Broadband, Cellular others
• Broadband (ADSL) remains the preferred choice
• Early issues with CDMA (cellular) are now largely
  resolved
• CDMA is an acceptable alternative system.
• Satellite radio investigated and viable as
  future options

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Operating Procedures

• The early Regional VMS set up as a series of
  small separated clusters operated independently
  of each other
• As VMS numbers increased, so to did the
  requirement to present information in a
  coordinated, consistent and timely manner
• VMS signs, structure design, and
  communication/control systems were becoming
  diverse and costly
• Major differences in message style, audience and
  format sprang up between different regions and
  different operators

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Operating Procedures - Message Format

• Being addressed by three initiatives to improve
  message consistency and comprehension
• First Second Initiatives
• National VMS Operating Policy - overarching rules
  based on international examples and established
  national regulations.
• Regional Operating Manuals - to assist operators
  and other stakeholders to display consistent
  messages constructed according to established
  international best practice, aligned with a New
  Zealand flavour.

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Operating Procedures - Message Format
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Operating Procedures - Comprehension

• Third Initiative VMS Message Comprehension by
  Opus
• Review of known international practice to
  establish best approaches to structuring and
  formatting VMS messages.
• Human factors assessment of proposed standard
  messages and message elements
• The outcomes of this work will in large part
  determine an optimal set of VMS messages for the
  entire country.

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Operating Procedures - Comprehension

• Human Factors Influencing Message Comprehension

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Operating Procedures - Comprehension

• Human Factors - Surprising!!
• The phaonmneal pweor of the hmuan mnid, aoccdrnig
  to a rscheearch at Cmabrigde Uinervtisy, it
  dseno't mtaetr in waht oerdr the ltteres in a
  wrod are, the olny iproamtnt tihng is taht the
  frsit and lsat ltteer be in the rghit pclae.

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Sometimes words are just not needed
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Standard Types of Regional VMS

• Key Design Considerations
• What information must be conveyed?
• Numbers of units of information, likely need to
  simultaneously display messages for multiple
  sections of highway, and/or multiple routes
• Balance potential information against space
  limitations, reading time available for
  motorists, ability of road user to assimilate
  and process gt8 to 10 units of information

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Standard Types of Regional VMS

• Generally possible to convey the key information
  for one section of highway on two lines

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Standard Types of Regional VMS

• Determining optimal character height is dependent
  on a number of factors. NZTAs approach is based
  on the UK standard considers
• The size of the message
• Traffic speed, number of lanes
• Traffic density
• Whether the sign is above or to the side of the
  carriageway

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Strategic Site Selection

• Must consider
• The important routes
• Frequently experienced adverse conditions and
  locations of incidents
• Alternative routes and detours
• Assess effectiveness of present management of
  adverse conditions determine whether the cost /
  benefits of installing a VMS are justified

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Strategic Site Selection
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Strategic Site Selection - Macro
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Specific Site Selection

• Long straight approach for adequate reading time
• Speed environment
• Width of the sign, supports, and foundation
• Sufficient space on the left side to safely
  accommodate support structure and any protective
  barrier
• Possible foundation or geotechnical issues
• Site exposure to excessive wind speeds
• Access for installation servicing the VMS
• Distance from an upstream or downstream
  intersection
• Access to mains power
• Access to broadband or CDMA
• Possible impact of light on neighbours
• The need to consult nearby land owners

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Support Structures

• The early VMS support structures were diverse
• Considerable variation in expected service life,
  operational performance, appearance,
  unnecessary costs through replication of design
  effort
• Standard support structures and foundation
  designs available for all VMS types, both dual
  post and single post supports.
• Innovative standard single post supports
  incorporating rotating heads and UHMWPE, for
  sites with restricted access

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Support Structures - Frangible

• Type D VMS are light enough to mount on frangible
  support structure
• Significant advantages
• Protective barrier not required
• Allows installation in narrow road reserve

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Support Structures - Frangible
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Conclusion

• Over the last couple of years NZTA have realised
  significant benefits from this project
• In some instances the benefits have exceeded the
  original value proposition
• The use and roles of VMS regionally has grown
  significantly, and they have now become one of
  the key tools for managing the network
• Murray Russell Neil Garnett
• NZ Transport Agency Opus International
  Consultants