Benefits and Types of Variable Message Signs

Variable Message Sign Operating at Night

Benefits and Types of Variable Message Signs


Variable Message Signs (VMS) are commonly used on roads, highways, freeways, motorways, tunnel entrances, and in rural areas throughout Australia. VMS are extremely beneficial for increasing road safety performance because they can directly signal to a motorist on the road, many types of information quickly and effectively. 
It’s more than likely that you would have driven past at least one of these electronic traffic signs or seen one as a passenger on your travels – can you recall the last time you saw one? 

Variable Message Sign A and C sized

Perhaps you were stuck in a traffic jam on the way home from work, getting frustrated as to why there was more traffic than normal. You ask yourself, what’s going on up ahead?  All of a sudden, you can see an electronic traffic sign explaining that there has been a traffic incident up ahead, along with an expected timeframe for the additional delay in travel time.  
Providing this type of information to motorists via a Variable Message Sign benefits the motorist by relaying information on why there is a delay using a few short phrases or words. This is just one familiar situation to all of us that might help you to begin to see the benefits of using one or more VMS in different road scenarios.
Let’s look at some additional benefits of having a Variable Message Sign for improved road safety. They increase road safety by communicating important traffic information directly to motorists. Below we have compiled a list of the 3 key benefits of using these important road safety tools.  


3 Key Benefits of using a Variable Message Sign  

  1. Reduces traffic congestion 

Traffic congestion is an ongoing transportation problem that motorists and road authorities encounter daily. The level of traffic congestion can rapidly increase with travel growth, roadway expansions, and developing infrastructure projects. These 3 main factors among many others can interrupt the desired capacity of motorists that can travel on roads, causing a significant amount of congestion. Although this work is paramount to growing communities this can be disrupting to motorist usual travel times, increasing driver frustration.  
As a result, the congestion can cause further delays, uncertainty in travel time and increase accident rates. So, how can we use a Variable Message Sign to help reduce congestion? 
When deploying a VMS, it’s worth considering the unexpected situations, like traffic incidents and emergencies, that occur daily on the road and cause congestion. Having a VMS in these situations can provide advanced warnings directly to road users to help them stay informed and make an alternate choice, wherever possible. 
In addition, setting up a VMS prior to planned road works beginning can provide notifications to motorists of future events, that may impact their journey. Providing this information well in advance can help a driver determine an alternative route, or even allow for more time to get to their destination thus reducing traffic congestion.


  1. Help to prevent road accidents 

In Australia, according to the National Road Safety Strategy the number of lives lost due to road related incidents are, on average, 1208 each year. Changing road conditions can provide an unexpected situation for motorists, particularly those that are used to travelling the same route each day on a familiar road. Using a Variable Message Sign to display advanced warnings to motorists, can help to prepare themselves for a change and could mean the difference between someone returning home safely or an unfortunate accident. 
When placed correctly Variable Message Signs can really help reduce the likelihood of crashes. More specifically rear-ended crashes. These accidents occur when traffic comes to a sudden, unexpected stop. Below are 2 examples where VMS can be used to help prevent accidents. 

Example A – Lane Closure Advanced Warning 

A VMS can be set up to provide advanced warning of an upcoming lane closure. The VMS informs the driver of a changing traffic condition they are about to enter. Alerting drivers of an upcoming lane closure prior to the actual closure, ensures the driver can make a decision and take the necessary action ahead of time.
Without VMS communication the driver could be left in shock by the road closure, which could result in last minute braking or worse, a collision. 

Example B – Speed Limit Changes 

Speed limit changes and alterations need to be communicated to all motorists. A Variable Message Sign can be used to provide a range of different speed limit change messages, including the display of an actual speed limit sign, as seen in the image below. This provides information to the motorist advising alterations on speed limit or the reason for a speed limit reduction. 

Variable Message Sign Displaying Speed 60Km


  1. Numerous Communication Options 

Both Permanent and Portable Variable Message Signs can display a range of messages, across one or more screens. This allows ability to communicate quickly and effectively with motorists.
In addition to displaying multiple messages, VMS can operate in conjunction with a range of accessories to provide further detailed traffic information, including:

  • Real-time traffic information relating to road incidents
  • Live estimated travel times
  • Detect and advise speed limits  

Having additional information for communication to motorists and the ability to delve deeper into data that can be analysed for many purposes. If you are interested in learning more about detailed traffic information, head over to our VMS product page to view the range of accessories that can enhance the capabilities of Mobile Variable Message Signs. 


Fixed vs. Portable Variable Message Signs

There are two main types of VMS, Permanent and Portable VMS. Both types of VMS come in a range of sizes for different applications. Fixed and Mobile Variable Message Signs have many similarities including dynamic messaging, remote programming, numerous communication options, and bright multi colour displays.  
However, the use and application of each type are different. As the name suggests Permanent VMS are often mounted on highway bridges and tunnel entrances in a place that they will remain long term. 
Alternatively, Mobile Variable Message Signs are trailer mounted for easy mobility. They can be easily moved from one location to another, for both short- or long-term usage. 


Permanent/ Fixed Variable Message Signs 

Permanent or Fixed VMS can be found in many different sizes, depending on the application, primarily in a large rectangle shape. They are designed to effectively deliver traffic information to motorists. Such as information reporting traffic congestion, temperature, lane controls, speed limits, and changes in usual traffic conditions. 
Occasionally known as Variable Message Signs Tunnel, as they are often equipped to tunnel entrances to display travel time and tunnel lane closures.
Permanent VMS are often used on highways, roadways and tunnel entrances. 

Permanent VMS - Vic roads


Mobile/Portable Variable Message Signs

Mobile Variable Message Signs have become a staple part in traffic management and community awareness projects, as they have been shown to effectively disperse traffic away from work sites, potential bottlenecks or known problem areas. Mobile VMS can be used for several different reasons including traffic management, roadworks, advertising, and events.
For traffic management application portable VMS can be used to advise road/lane closures, communicate with a motorist and local traffic of any changes usual traffic conditions, providing directional information, displaying safety information, accident management and speed related messages. 

The below images are slides from a portable variable message sign advising a road closure ahead. 



For Both Fixed and Mobile Variable Message Signs to successfully communicate with motorists, messages must be easy to read and comprehend. At RPM Hire our team of traffic management equipment hire specialists can assist with portable Variable Message Sign hire and effective messaging. Call us 1300 479 570 or send an enquiry via our contact form.

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