Variable Speed Limit Signs

Variable Speed Limit Signs

What is a Variable Speed Limit Sign

Variable Speed Signs are signs used to moderate traffic and driving patterns by automatically raising or lowering the posted speed limit based on various conditions. These signs are often triggered by conditions such as:

  • Increased Congestion (Rush Hour)
  • Reduced Visibility
  • Reduced Road Friction Caused by Poor Weather
  • Downstream Incident and Queue Detection
ATMS systems use advanced algorithms to analyse various data sets received from the field and when pre-set conditions are met the system triggers a speed limit increase or decrease (between maximum and minimum speed)

What's involved with deploying one of these systems?

The primary components required for this type of system is as follows:

  • Field Sensors Collecting and Transmitting Data(Most often RTMS/RWIS)
  • Central Software System Analyzing Field Data and Providing Sign Changes
  • Variable Speed Limit Signs Receiving Sign Change Information From Central System

What kind of signs are available?

The two sign types used for this application are:

  • Prismatic Based Electro-Mechanical Signs
  • Small Electronic Message Signs