Skip to content

Important notice

The building where our contact centre is based was evacuated last week. Our 0800 numbers are up and running again, but please be patient as we have limited support available for our contact centre staff. We’ll do our best to help you if you need to call us.  For more information read our latest media release.

Access keys for nzta.govt.nz

  • h Home
  • m Menu
  • 0 Show list of access keys
  • 2 Skip to content
  • 3 Skip to top
Back to Resources

Research Report 005 Installation and maintenance of inductive detector loops

Published: | Category: Integrated land use and transport systems , Research programme , Research & reports | Audience: General

Inductive Loop Detectors (ILDs) are the most common form of vehicle detection for vehicle activated traffic signals in use today. They consist of a number of loops of wire buried in the roadway pavement and connected to a detector unit or amplifier.

Accurate and reliable detection of vehicles is required to minimise delays, stops and fuel use of vehicles passing through an intersection. For example a recent study in Sydney estimated savings from improved detector performance of A$23 million were possible for that metropolitan area.

This report provides a practical guide to the installation of the loop in the roadway to increase the reliability of that component of the ILD. Different commonly used methods are explained and their advantages and disadvantages discussed in relation to simple theoretical and practical considerations. This is to enable practitioners to use some judgement in applying the techniques to their particular conditions. Important aspects are the type of wire used and the type of sealant used to seal the sawcut slot in the pavement after the wires have been laid in it. The recommended sealant is a flexible epoxy material. A more detailed description of some theoretical aspects of ILD's is contained in an Appendix.

An Instruction Leaflet for Installing Standard Detector Loops is included in which the recommended method for installing loops in standard situations is set out in the form of simple instructions for field staff.

Keywords: Detectors, vehicle detectors, inductive loops, inductive loop detectors, traffic, traffic control

Publication details

  • Author:
  • Published: 1991
  • Reference: 5
Top