Other Surveys

Other surveys undertaken by TAPS include:

• School Crossing Surveys
  These surveys involve the collection of children crossing numbers and traffic volumes at the key crossing times of the day. These surveys are typically undertaken to support applications for new school crossings or school crossing supervisor subsidy applications/maintenance. Surveys can either be done manually of by video analysis.
  

• Pedestrian Crossing Surveys
  Similar to School Crossing Surveys but typically undertaken to support applications for the installation of Zebra Crossings or Pedestrian Operated Signals.
  

• Gap Studies 
  Surveys can be undertaken of the opportunity for vehicles to enter or cross a main road from a side road or driveway. This type of survey can be undertaken either by a surveyor on site measuring the gaps in the main road traffic using an electronic data-board designed for this purpose or a by video survey.
  

• Queue Length Studies
  These studies can be undertaken on the approaches to intersections where signal control, roundabout or other controls lead to vehicle queuing. Typical parameters that might be measured include:
  o  Maximum stationary queue defined as the length of the queue when signals turn green;
  o  Maximum back of queue defined as the length of queue when the last stationary vehicle in the queue moves;
  o  Overflow queue is defined as the number of vehicles still left in the queue when the lights change to red.
  These surveys are typically undertaken with on-site observers but can also be undertaken using video surveillance.
  

• Manual Vehicle Classification Studies 
  These studies are short-term observational studies of the classification of vehicles. Typical classifications might include:
  o  Light Vehicles, that is cars, vans, utilities etc. singly or towing
  o  Single Unit Trucks
  o  Single Unit Trucks towing
  o  Semi-trailers
  o  B-doubles.
  Other classifications might include observation of hazardous good carrying vehicles or numerous other options.
  

• Origin-Destination Surveys 
  surveys are undertaken by defining a cordon around the area of interest. Each road crossing of the cordon is defined as a station. At each station a sample of vehicles entering or leaving the cordon is recorded together with the time. Traffic counts need to be undertaken at each of the cordon sites to allow an assessment of the expansion factors required to adjust the sampled origin/destinations to represent the traffic flows. Typically only four digits of a number plate are recorded to reduce the survey task and also to mitigate privacy issues.
  
  The sample can either be defined by only recording say white or red vehicles or only number plates ending with the number 1 or 2.
  
  The recorded numbers entering/leaving the cordoned area are then matched together with the time between sightings to allow an assessment of the origins/destinations of vehicles passing through the cordon and whether the vehicles had a stop within the cordon.
  
  O/D Surveys are subject to a number of possible errors, these include:
  o  Errors in recording of numbers including missing a vehicle at one or more station, transposing numbers or simple
     errors in recording the numbers;
  o  Errors in matching due to only recording partial number plates.
  

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Ph. 9874 7834